Inheritance and Complementation: A Case Study of Easy Adjectives and Related Nouns

Deutsches Forschungszentrum für Künstliche Intelligenz GmbH Research Report RR-91-30 Inheritance and Complementation: A Case Study of Easy Adjectives and Related Nouns Dan Flickinger and John Nerbonne September 1991 Deutsches Forschungszentrum für Künstliche Intelligenz GmbH Postfach 20 80 67608 Kaiserslautern, FRG Tel.: + 49 (631) 205-3211 Fax: + 49 (631) 205-3210 Stuhlsatzenhausweg 3 66123 Saarbrücken, FRG Tel.: + 49 (681) 302-5252 Fax: + 49 (681) 302-5341

Deutsches Forschungszentrum für Künstliche Intelligenz The German Research Center for Artificial Intelligence (Deutsches Forschungszentrum für Künstliche Intelligenz, DFKI) with sites in Kaiserslautern and Saarbrücken is a non-profit organization which was founded in 1988. The shareholder companies are Atlas Elektronik, Daimler-Benz, Fraunhofer Gesellschaft, GMD, IBM, Insiders, Mannesmann-Kienzle, Sema Group, Siemens and Siemens- Nixdorf. Research projects conducted at the DFKI are funded by the German Ministry for Research and Technology, by the shareholder companies, or by other industrial contracts. The DFKI conducts application-oriented basic research in the field of artificial intelligence and other related subfields of computer science. The overall goal is to construct systems with technical knowledge and common sense which - by using AI methods - implement a problem solution for a selected application area. Currently, there are the following research areas at the DFKI: 2Intelligent Engineering Systems 2Intelligent User Interfaces 2Computer Linguistics 2Programming Systems 2Deduction and Multiagent Systems 2Document Analysis and Office Automation. The DFKI strives at making its research results available to the scientific community. There exist many contacts to domestic and foreign research institutions, both in academy and industry. The DFKI hosts technology transfer workshops for shareholders and other interested groups in order to inform about the current state of research. From its beginning, the DFKI has provided an attractive working environment for AI researchers from Germany and from all over the world. The goal is to have a staff of about 100 researchers at the end of the building-up phase. Dr. Dr. D. Ruland Director

Inheritance and Complementation: A Case Study ofeasyadjectives and Related Nouns Dan Flickinger and John Nerbonne DFKI-RR-91-30

This work has been supported by a grant from The Federal Ministry for Research and Technology (FKZ ITWM-ITW 9002 0). cdeutsches Forschungszentrum für Künstliche Intelligenz 1991 This work may not be copied or reproduced in whole of part for any commercial purpose. Permission to copy in whole or part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of the Deutsche Forschungszentrum für Künstliche Intelligenz, Kaiserslautern, Federal Republic of Germany; an acknowledgement of the authors and individual contributors to the work; all applicable portions of this copyright notice. Copying, reproducing, or republishing for any other purpose shall require a licence with payment of fee to Deutsches Forschungszentrum für Künstliche Intelligenz. ISSN 0946-008X

InheritanceandComplementation:ACaseStudyofEasy AdjectivesandRelatedNouns DeutschesForschungszentrumfurKunstlicheIntelligenz PaloAlto,California94304-1126 Hewlett-PackardLaboratories ickinger@hplabs.hp.com 1501PageMillRoad JohnNerbonne DanFlickinger D-6600Saarbrucken11,Germany nerbonne@dfki.uni-sb.de Stuhlsatzenhausweg3 volume.ourstudyservestohighlightsomeofthemostusefultoolsavailableforstructuredlexical guagehavebeenunderactivedevelopment,asisevidentintherecentstudiescontainedinthis Abstract Mechanismsforrepresentinglexicallythebulkofsyntacticandsemanticinformationforalan- November4,1994 illustratesthevalueofthesemechanismsinilluminatingonecornerofthelexiconinvolvingan unusualkindofcomplementationamongagroupofadjectivesexempliedbyeasy.thevirtues extendtheanalysisofadjectivalcomplementationinseveraldirections.thesefurtherillustrate howtheuseofinheritanceinlexicalrepresentationpermitsexactandexplicitcharacterizations ofthestructuredlexiconareitssuccinctnessanditstendencytohighlightsignicantclustersof ofphenomenainthelanguageunderstudy.wedemonstratehowtheuseofthemechanismsemployedintheanalysisofeasyenableustogiveauniedaccountofrelatedphenomenafeaturing nounslikepleasure,andeventheadverbs(adjectivalspeciers)tooandenough.alongthewaywe motivatesomeelaborationsofthehpsg(head-drivenphrasestructuregrammar)frameworkin whichwecouchouranalysis,andoerseveralavenuesforfurtherstudyofthispartoftheenglish lexicon. representation,inparticular,(multiple)inheritance,defaultspecication,andlexicalrules.itthen linguisticproperties.fromitssuccinctnessfollowtwopracticaladvantages,namelyitseaseof maintenanceandmodication.inordertosuggesthowimportantthesemaybepractically,we undtechnologietothedfkidiscoproject. workwaspartiallysupportedbyaresearchgrant,itw90020,fromthegermanbundesministeriumfurforschung forfrequentconversationsaboutthisanalysis.wearealsogratefultoanthonykroch,theparticipantsatthe TilburgWorkshoponInheritanceinNaturalLanguageProcessing,andthreerefereesforfurthercomments.This 1Introduction Thelexiconisalargeandcomplexsetofinformationaboutthewordsusedinagrammaror naturallanguageprocessingsystem.itsimportancehasbecomemorecentralintheresearchof WeareindebtedtoMarkGawron,MasayoIida,BillLadusaw,JoachimLaubsch,CarlPollardandTomWasow 1

thepastdecade,whichhasseentheriseofradicallylexicalizedtheoriessuchashead-driven phrasestructuregrammar(hpsg),inwhichphrasestructurerulesplayavestigialrole. Newertheoriesplaceincreasinglyhighdemandsonlexicalrepresentation.Asimplecalculation mayillustratethequandaryoflexicalrepresentation:featuresystemsforcontemporarysystems normallydistinguishatleast30features(while40or50isnotrare).thenumberofvaluesa featuretakesrangesfrom2tothenumberofcategories(moreexactly,tothenumberofsequences orsetsofasmallsize,whereallthemembersofthesequence,etc.arecategories).underthe undoubtedlyoptimisticassumptionthatfeaturevaluerangescouldbereducedtobooleans,westill arefacedwith230=109featurecombinations whoseindividualrepresentationisclearlytobe avoided,not\solved".1thenaturaltackiscertainlytorepresentjustthecategoriesactuallyused inthevocabulary,butthiscouldincuragooddealofredundancyifitmeantthateachfeature combinationwererepresentedseparatelyoneachword. Thestructuredorhierarchicallexiconsolvesthisdiculty(cf.Flickinger,Pollardand Wasow,1985andFlickinger,1987).Instructuredlexicons,wordclassesmaystandinarelationship ofinheritancetooneanother,inwhichcasethepropertiesofthebequeathingclassaccrueautomaticallytotheinheritingclass.onceweallowthatasingleclassmaybeheirtomorethanone bequeathingclass,weallow,inprinciple,thatnowordclasspropertyeverneedbeexaminedmore thanonce.thusweeliminateonecentralsourceofredundancyinlexicalspecication.oneofthe goalsofthispaperistomotivatetheuseofinheritanceinlexicalspecication.todothis,wetake anarrowlycircumscribedphenomenoninenglishgrammar thatofvp-complement-takingadjectives,asinhard+todeliver andspelloutthelexicalspecicationswhichathoroughtreatment demands.thesheercomplexityofthesespecicationscriesoutforaredundancy-eliminatingapproach,andweproposeastructuredlexicontreatment.thegrammaticalanalysisnotonlyserves tomotivatethegeneralapproach,italsoillustratesseveralkeyissuesinthedesignofstructured lexicons,suchastheuseofdefaultinheritance,theneedforlexicalrules,andtherangeof phenomenaamenabletothissortoftreatment. Thegoalsofthispaperaretointroducethestructuredlexiconinafairlysimpleform,to motivateitsbasictheoreticaldevice,thatofinheritance,witharealexampletakenfromanexisting system,andnallytoshowhowtheeliminationofredundancyachievedwiththestructuredlexicon aidsinmaintainingthelexicon.weargueforimprovedmaintainabilitybyexaminingconcrete extensionsandpotentialmodicationsofthegrammaticaldescriptionprovided.weturnnowto abriefcharacterizationofthisphenomenon. Therichcollectionofsyntacticandsemanticphenomenaexhibitedbyafamiliargroupof adjectivesliketoughandeasypresentachallengetothosewhoseektoprovideexplicitformal characterizationsoflinguisticproperties.weoerhereadetaileddescriptionoftheproperties oftheseadjectives,involvingoptionalandobligatorycomplementation,control,long-distance dependence,optionalmodication,andspecication.thepurposeofthisdescriptionhereis notthelinguisticanalysisitself(whichwendinteresting,nonetheless),butratheritsusein demonstratingthepracticalutilityofinheritanceasatoolforlinguisticdescription,andalsothe predictiveanalyticalpowerthatinheritanceaordsinthestudyofthelexicon.inillustrationofthe latter,weextendouranalysisofeasyadjectivestoasimilargroupofnounssuchaspleasure,and thentotheunusualadverbstooandenough,whichfunctionasspeciersinadjectivalgradation. Thefundamentaldataareillustratedin(1);examplessuchasthesehavenotattractedattention incomputationallinguistics,eveniftheyhaveoftenappearedinstudieswithinthegenerative framework.anearlydiscussionofthemisfoundinmillerandchomsky(1963),withascoreand moreofadditionalstudiespublishedintheyearssince.mostofthesalientpropertiesofthese adjectiveshavealreadybeenbroughttolight,butinpiecemealfashionandmostoftenaspartofa largerdebateaboutthenatureofunboundeddependencies,wheredetailedsyntacticandsemantic characterizationsofthesemissingobjectconstructionsprovedlessimportant.2wereturntothe 1Cf.Gazdaretal.,1985,Appendixforasmallgrammarwhichnonethelessexceedsthesizespeculatedonhere. 2RelatedworkintheoreticalanddescriptivelinguisticsincludesChomsky(1965),Rosenbaum(1967),Ross (1967),Postal(1971),Bresnan(1971),Chomsky(1973),LasnikandFiengo(1974),Jackendo(1975),Chomsky (1977),Fodor(1978),Brame(1979),Nanni(1980),Schachter(1981),Jacobson(1982,pp.221-23),Sag(1982),Maling andzaenen(1982,pp.253-54),kaplanandbresnan(1982,pp.255-63),culicoverandwilkins(1984),jacobson 2

characteristicpropertiesoftheseadjectivesinsection3,wheretheyarecataloguedandgiven formalrepresentation. (1)a.Billiseasytotalkto. b.itiseasytotalktobill. c.billiseasyformarytotalkto. d.itiseasyformarytotalktobill. Wechosethisphenomenonasavehicletorecommendlexicalinheritancebecauseitillustrates awiderangeofgrammaticalphenomena,allofwhichmakedemandsonlexicalresources(at leastinthelexicalizedgrammarinwhichtheanalysisisframed).inadditiontothegrammatical demands,thedatajustifytheuseofalexicalrule(derivationalrule)torelatepairssuchas(a)and (b)in(1) soweshallargueatanyrate thusillustratingafurtherinheritance-likerelationship inthelexicon. Theremainderofthepaperisstructuredasfollows:Section2summarizestheaspectsof HPSGwhichareimportanttoourproposal,andSection3developsthefundamentalanalysis, whichsection4illustratesinaseriesofanalytical\snapshots"ofasingleexample.section5 suggestsextensionsofthefundamentalanalysis,especiallytofurtherlexicalclasses(developing theargumentthatstructuredlexiconsareeasilymaintainedandextended),andanalsection summarizesandsuggestsdirectionsforfuturework.appendixapresentstheframeworkfor lexicaldescriptiondevelopedinflickingeretal.(1985)andflickinger(1987).theframeworkis convenientforfeature-basedgrammars,butitallowsthespecicationofotherlexicalproperties aswell.thisappendixpresentsanotationwhichisprecisewhileavoidingredundancy,e.g., incharacterizingthekindsofcomplementsthattheseadjectivespermit,andinexpressingthe relationshipsthatholdbetweenpairsliketheeasyof(1a)andthatof(1b).sinceafundamental claimofhierarchicallexiconsisthattheyeliminateredundancyandthusimprovemodiability, thereisasecondappendix,appendixb,whichdemonstratesthemodiabilityofthestructured lexicon. 2GrammaticalTheory Thephenomenainvolvedintheanalysisoftheeasyadjectiveclassillustrate(obligatoryandoptional)subcategorization,control,long-distancedependence,optionalmodication,andspecication (thelastinitsinteractionwithadjectivalgradationwithtooandenough).assuch,itrepresents anexcellentdemonstrationvehicleforthelexicaldemandsofgrammaticalanalysis.ouranalysisisformulatedwithinhead-drivenphrasestructuregrammar(hpsg),thegrammatical theorydevelopedbycarlpollardandivansagduringthemidandlate1980's.seepollard(1984), Pollard(1985),PollardandSag(1987),Pollard(1988),PollardandSag(1988),Pollard(1989), andpollardandsag(1991).asthelengthylistofpublicationsmightsuggest,thisgrammatical theoryiswellenoughdocumentedsothatwemayrestrictourremarksheretothedistinctive characteristicsoftheassumptionsusedhere.weassumefamiliaritywithfeature-basedgrammars andbasicfamiliaritywithhpsgaswell. Inalllinguistictheoriesthereisadivisionoflaborbetweengrammaticalrulesandthelexicon, andthisconcernstheamountofinformationcontainedineach.attherule-basedextremelie non-feature-basedcontext-freegrammars,wherethelexiconmerelylinkslexicalitemstononterminals;inthesegrammarsitisindeedcustomarytoviewthelexiconasasetofunaryrules.the grammaticalrulesthusencodeeectivelyalllinguisticinformation.atthelexicalextremewe (1984),Gazdar,Klein,Pullum,andSag(1985,pp.150-52)(hence:GKPS),Jacobson(1990),Jones(1990),Bayer (1990),andHukariandLevine(1991).Noneoftheseworkshaveattemptedathoroughdescriptiveanalysisofthe rangeofdataweaddresshere,thoughweareofcourseindebtedtothesestudiesformuchofthedataandmanyof thegeneralizationsweseektoexpress.inparticular,ouraccountisconsistentwiththebriefgeneralizedphrase structuregrammar(gpsg)analysisoftheseadjectivesgiveningkps(1985,pp.150-2)thoughweembracea largerrangeofdataandextendtheanalysistorelatednouns,atopicrarelydiscussedsinceitsintroductionby LasnikandFiengo(1974). 3

ndfeature-basedcategorialgrammars,whichallowfunction-argumentapplicationastheonly grammaticalrule.herethelexiconbearstheburdenofencodinglinguisticinformation,andthe contributionofrulesismarginal.weemphasizethathpsgisfoundveryclosetothelexicalextreme,becausethishighlightsthesignicanceofthepresentwork HPSGisaframeworkwhose lexicaldemandsareverynearlymaximal. SubcategorizationinformationislexicallybasedinHPSG,muchasitisinCategorialGrammar(Bach,1988).Grammaticalheadsspecifythesyntacticandsemanticrestrictionstheyimpose ontheircomplementsandadjuncts.forexample,verbsandverbphrasesbearafeaturesubcat whosecontentisa(perhapsordered)setoffeaturestructuresrepresentingtheirunsatisedsubcategorizationrequirements.thusthefeaturestructuresassociatedwithtransitiveverbsinclude theinformation: subcat:hnp case:acc;np case:nomi (wherenpabbreviatesasubstantialfeaturestructure.)appliedtoadjectivalvpcomplementation,thistreatmentofsubcategorizationleadsnaturallytothepostulationofadjectiveswhich subcategorizeforvp's,etc.(detailsbelow). Thesignicanceofsubcategorizationinformationisthatitrepresentsa(perhapsordered)set ofgrammaticalcategorieswithwhichasubcategorizercombinesinforminglargerphrases.when asubcategorizercombineswithasubcategorizedelement,theresultantphrasenolongerbearsthe subcategorizationspecication ithasbeendischarged.cf.pollardandsag(1987,p.71)fora formulationofthehpsgsubcategorizationprinciple. Weshallingeneralpresentsubcategorizationspecicationsinaslightlydierentwayfromthat above,i.e.,notasasinglefeaturewhosevalueisalist,butratherasacollectionofcomplement featureswithcategoryvalues.cf.borsley(1989)foradevelopmentofthisapproach,which weshallnotattempttojustifyhere.wewillthereforereorganizetheinformationaboveinthe followingway: 264subject:NP case:nom object:np case:acc375 Wechoosethisrepresentationhereonlybecausewendthekeywordingofgrammaticalfunctions, subject,etc.,moreperspicuousthananencodingintermsoflistpositions,butnothinginthe analysishingesontheoneortheotherrepresentation. Weshallfurthermoreallowthatsubcategorizedelementsbeeitherobligatorilysubcategorized oroptionallysubcategorized.optionallysubcategorizedelementsneednotbedischargedfrom subcategorizationspecications.(thisnecessitatesanobviouschangetotheprinciplethatsubcategorizationmustbesatisedinindependentutterances.)incaseanelementisnotdischarged, somethingmustbesaidaboutitssemantics.hereweborrowanideafromsituationtheory,and specifythatunsaturatedpredicate-argumentstructures(orinfons,seedevlin,1991)mayhold whenthereissomewayofllingouttheunlledargumentpositionssothattheresultholds.this hastheeectofexistentiallyquantifyingoverunlledargumentpositions.linguistically,there aremanyotherwaysinwhichargumentsmaybeomitted(cf.fillmore1985),butthisseemsto sucefortheadjectivesunderexaminationhere. Controlandmodification,thelatterbeingtherelationbetweenanadjunctandahead,are bothlexicallyrealizedinthecaseoftheeasyadjectives.weregardthereasbeingacontrolrelation betweenforsmithandtogetincomplexadjectivalssuchaseasyforsmithtoget(cf.gkps1985: 83).Modicationplaysarolewhencomplexadjectivalsappearinconstructionwithnominal heads,asineasyjobforsmithtoget.thesearecommonassumptionsintheanalysesofcontrol andmodication. Long-distancedependenceistreatedinHPSGinmuchthesamewayitwastreatedin GPSG(cf.GKPS,1985),andweassumebasicfamiliaritywiththistypeofanalysis.Werecall 4

isaspecicationoftheexpectedmaterial.theslashspecicationispropagatedbygeneral thatthesiteofamissingelementina\gappy"constituentbearsafeatureslash,whosevalue astallerthanitiswide.weshallrequirelexicalspecicationsthatleadtofeaturestructures principles(whichweshallnotelucidate)tothehigherlevelconstituents,untilitismatchedby ofthefollowingform: withannpinslash.itisunusualtondasubcategorizationspecicationforslash,butnot unique:comparativeslikewisesubcategorizeforgappycomplements,asinseeninexamplessuch exploitthisintheanalysisofseveralwordclassesbelow,viz.,theoneswhichsubcategorizeforavp a\ller"orasubcategorizingelement.whenthegappyconstituentisadjoinedtoalleror subcategorizingelement,theresultnolongerbearstheslashvalue. containagap.(cf.gkps,1985,pp.150-53fortherstmentionofthissuggestion.)weshall Importantforourpurposesisthepossibilityofalexicalentryspecifyingthatadependentmay 264 sem:easy(1;^2) stem:easy syn.loc.subcat:2 6 4 subj: pp-for:hsem:1i xcomp:264syn:vp-inf syn:np-nom sem:3 slash:hsem:3i375 sem:2 subjectsemanticshavebeenidentied.thus,onceavp/nphascombinedwiththisadjective, thesemanticcontributionoftheslashelementisassumedbythesubject.figure1showsan Thetag3inthediagramaboveshowsthatthesemanticsoftheSLASHvalueandtheadjectival 3 75 3 analysistreeforanexamplecontainingalong-distancedependency. Thevarietyoflinguisticphenomenaexempliedintheeasy-classofadjectivesguaranteesthat 75 Thefundamentaldataweshallbeconcernedwitharerepeatedin(2): follow,butweprovideanoverviewofthesemechanismsforlexicalrepresentationinappendixa. Weassumefamiliaritywiththemechanismsoflexicalinheritanceandlexicalrulesintheanalysisto 3AdjectivalVPComplementation itisademandingtestinggroundfortheoriesoflexicalrepresentation.3 (2)a.Billiseasytotalkto. b.itiseasytotalktobill. c.billiseasyformarytotalkto. thetheoreticalliterature:proudianandpollard(1985),nerbonneandproudian(1987),franz(1990),emeleand Zajac(1990),andCarpenter,PollardandFranz(1991). safelyreferthereadertodocumentationsofthoseimplementations,evenifthesearelessgenerallyavailablethan StanfordUniversity,CarnegieMellonUniversity,TheOhioStateUniversity,SimonFraserUniversity,University pastseveralyears;weknowofimplementationsathewlett-packardlaboratories,thegermanaicenter(dfki), ofedinburgh,icot,universityofstuttgart,theibmlilogprojectinstuttgart,andatr.wemaytherefore 3ItisalsoworthmentioningthatHPSGhasalsobeenthesubjectofintensiveimplementationactivityduringthe Otheradjectivesthatshowthissamedistributionincludethefollowing: d.itiseasyformarytotalktobill. 5

NP S These Det LLLLN????@@@@VP books Vare JJJJAdjP easy TTTT Vto TTTT VP/NP VVP/NP have TTTTS/NP Bob AAAA VVP/NP read LLLL NP/NP \slashed"np,i.e.,avpmissingannp(whoseexpectedpositionmaybearbitrarilydeep). Figure1:ComplexadjectivalssuchaseasysubcategorizeforacomplementVPcontaininga t 6

amusingdepressinggreat nice annoyingdiculthard painful boring exhaustingimportanttiresome comfortablefun impossibleterrible confusinggood impressivetough (3)Givenpairslike(2a,b)and(2c,d),twoclustersofpropertiesbegintosuggestthemselvesaspart ofthedenitionsoftherelevantlexicalentries.therstoftheseclusterswewillassociatewith theclassofwordscontaininglexicalentriesfortheeasyof(2a,c)anditscounterpartsin(3),aclass wetermslash-easy.theotherclusterofpropertiesweassociatewithasecondclasstermed IT-EASY,containingthelexicalentriesforthevariantofeasyin(2b,d)anditscounterpartsin (3).Webeginbysimplyidentifyingtherelevantpropertiesineachofthesetwoclasses,supported byexamplesasnecessary;thenweprovidemotivationforfactoringthesepropertiesintoseveral wordclasseslinkedbyinheritance. AdjectivesintheIT-EASYclasshavetwoobligatorycomplements,anNPsubjectandaverbal complement;inadditiontheyhaveoneoptionalcomplement,appheadedbytheprepositionfor. Asseenin(4),theverbalcomplementcanbeeitherinnitivalorgerundive,and(5)showsthat thiscomplementcanbeavpevenwithapp-forpresent,oraninnitvals,againwithorwithout theoptionalpp-forcomplement.thesubjectnpmustbetheexpletiveit. (4)a.ItwasgreatworkingforBill. b.itwasgreattoworkforbill. (5)a.It'seasiestforthedogstofeedthematnoon. b.forthedogs,it'seasiesttofeedthematnoon. c.it'seasiestforthedogstobechainedupallday. d.*forthedogs,it'seasiesttobechainedupallday. e.it'seasiestformeforthedogstobechainedupallday. f.forme,it'seasiestforthedogstobechainedupallday. (5e,f)demonstratethatnotonlyVPcomplementation,butalsoScomplementationisinvolved ineasysubcategorization.notethatscomplementationneverrequiresacontroller,andthat theppphraseinsuchstructuresismobile(5f).inadditiontotheconclusionthatavarietyof complementationschemesareusedwitheasy,thedataabovealsodemonstratethattheexact specicationofthecontroller(theunderstoodsubjectoftheinnitivalvp)isnontrivial.(5a) demonstratesthatthepp-forcomplementneednotcontrolthevp,and(5b)suggeststhat noncontrollingpp'saremoremobilethancontrollers(5d). Weaccommodatethesefactssemanticallybyallowingthateasyandsimilaradjectivesdenote two-placerelationsbetweenindividualsandstatesofaairs.therelationholdsbetweenthepair, roughly,whenitiseasy(orconvenient)fortheindividualwhenthestateofaairsobtains.(5e,f) showthattheindividualinvolvedintheeasyrelationneednotbeinvolvedinthestateofaairs, i.e.thatthereisnonecessarysemanticcontrolinvolvedinthisrelation.4thecontrolfactsare clearenough:whenthiseasyiscombinedwithans,thereisnosemanticcontrol;andwhenit iscombinedwithavp,thereisnogrammaticallyspeciedcontrollerofthevp althoughthere maybepragmaticinferenceabouttheunderstoodsubject. AdjectivesintheSLASH-EASYclassalsohavetwoobligatorycomplements,anNPsubject andaverbalcomplement,aswellasanoptionalpp-forcomplement.incontrasttotherstclass, thisclassspeciesthatthesubjectisanormal(non-expletive)np,andthattheverbalcomplement 4Thereisaninterestingpragmaticproblemlurkinginthecontrolspecicationsinvolvedhere.Ifonespecies thecontrolrelationshipsexactly,thenoneneedstopostulatesystematicstructuralambiguityinexamplessuchas (5c),wherethesequenceofPPandVPmayormaynotbeanalyzedasanSconstituent.Thisseemsplausible, butthenwewouldliketohaveapragmaticaccountofwhythereisnormallynodistinction,i.e.,whythecontrol relationshipisinferred,or,equivalentlyforallintentsandpurposes,whythesreadingissostronglypreferred. 7

mustcontainannpgap.moreover,thisverbalcomplementmustbeinnitival,notgerundive,as seenin(6),andmustbeavp,notans,asshownin(7).5 (6)a.Billwasgreattoworkfor. (7)a.Forme,Billwaseasytotalkto. b.*billwasgreatworkingfor. thetwovariantsofeasyintroducedabove,butwhichmustbekeptdistinct.lasnikandfiengo twointermediatewordclassesthatwillstandbetweencontrolandthesetwointhehierarchy. immediatesubclassofcontrol;wedrawonthedataprovidedin(8)and(9)belowtomotivate TROLwhichintroducesaverbalcomplement,andwhichservesasthesuperclassfromwhich bothoftheclassesit-easyandslash-easyinherit.however,neitheroftheseclassesisan TheEnglishlexiconcontainstwomoregroupsofadjectiveswhichhavemuchincommonwith Inthewordclasshierarchyweassume,sketchedinAppendixA,thereisawordclassCON- b.*billwaseasyformeformarytotalkto. (1974:535)identiedasetofadjectivesincludingprettyandmelodious,illustratedin(8). (8)a.Disneylandisprettytolookat. b.sonatasaremelodioustolistento. entrywithanexpletiveitsubject,andsecond,theyassignarealthematicroletotheirsubjects. buthavetwosignicantdierences:rst,asshownby(8c,d),theydonothaveacorresponding MembersofthisclassofadjectivessharemuchincommonwiththeSLASH-EASYadjectives, f.?sonatasaremelodiousforseriousmusicianstolistento. c.*itisprettytolookatdisneyland. d.*itismelodioustolistentosonatas. thevalidityofthisinference,sincethesubjectoftheadjectiveplaysnodirectroleintherelation placerelationsuggestedaboveforit-easyandslash-easyadjectivescouldnotaccountfor Thatis,(8a)entailsthatDisneylandispretty,while(1a)doesnotentailthatBilliseasy.Thetwo- e.?disneylandisprettyforchildrentolookat. whatsoever.adistinctsemanticrelationiscalledforhere,oneinwhichthesubjectdoesplaya role(whicheectivelymakesthisclassakindofequiadjectiveincontrasttotheraisingeasy). easyin(1c),thoughjudgmentsarelessclear.inordertoexpressthesedierences,weintroducea ItalsoappearsthattheseadjectivesdonotpermittheoptionalPP-forcomplementlicensedby adjectivesof(1b,d),butwithnocounterpartsoftheslash-easytype. classslash-compwhichwillincludetheentriesforprettyadjectives,andwhichwillalsoserve astheclassfromwhichslash-easyinherits.6 Similarly,EnglishhasasetofadjectiveswhichhavemuchincommonwiththeIT-EASY (9)a.ItispossibletotalktoBillonlyatbreakfast. b.itisunnecessarytorebill. takeagerundivecomplementinsteadoftheusualinnitivalcomplement,asinthatarticleisnotworthlooking at.theextensionofouranalysistoworthisstraightforward,butnotgivenhere. isthattheformerdonotpermitanoptionalpp-forphrasecomplement;theydoallowtheverbal complementtobeeitheravporans(containingapp-forsubject),but(10)showsthatifa 5HukariandLevine(1991)noteinpassingthatthereisagroupofcloselyrelatedadjectiveslikeworthwhichdo ThesecondprincipaldierencebetweenadjectiveslikepossibleandthoseoftheIT-EASYclass c.*billispossibletotalktoonlyatbreakfast. 6OtheradjectivesofthisSLASH-COMPclassincludedelicious,handsome,attractive,andlovely. d.*billisunnecessarytore. 8

PP-forispresent,itmustbecontainedwithintheScomplement. (10)a.ItisunnecessaryforMarytoreBill.(MringB) b.*formary,itisunnecessarytorebill.(mringb) c.*itisunnecessaryformaryforyoutorebill. Again,weexpressthedistinctionbetweenthesetofadjectiveslikepossibleandtheIT-EASY adjectivesbyintroducingafourthclassit-subjparalleltoslash-comp.7 Thesefourclassdenitions,togetherwithonesupportingclass,aregivenin(11-16),withthe Superclassesattributeshowingtherelevantinheritancerelations. (11)IT-SUBJ Superclasses Control Complements Subject-Features(NFormit) Subject-Rolenone XComp-features(VFormInnitival)(Complete+{) Thedisjunctivespecication(Complete+{)overridesthedefault(Complete{)speciedin thecontrolclass,andmeansthattheverbalcomplementmaybeeitheravp(complete{) orans(complete+). (12)SLASH-COMP Superclasses Control Complements XComp-Subj-Semanticsx XComp-features (SLASH(CategoryNoun) (NFormNormal) (Complete+) (Predicative{) (CaseAccusative)) (Semantics Subject-Semantics)) TheSLASHfeatureontheXCompspeciesthattheVPmustcontainagapwhichisfora normal(non-expletive)nounphrasewhichisaccusativecase,andwhichisnotpredicative.this nonpredicativespecicationservestoexcludeexampleslike*billisdiculttobecome.assuming thecomplementofbecomeispredicative,sincethegapforthatcomplementwouldfailtosatisfy therestrictiononslashgivenin(12).theslashspecicationfurthermorenotesthatthe SLASHsemanticvalueisidenticaltothatofSubject-Semantics.AswasexplainedinSection3 above,thisistheformalexicalspecicationofsemanticcoindexingtakes. ThecontrollerofthecontrolledcomplementisspeciedthroughtheattributeXComp-Subj- Semantics;forexample,inCONTROL,thisattributehasthevalueSubject-Semantics,since subjectsaredefaultcontrollers.butthecomplementsofslash-comparenotgrammatically controlled(cf.(8e,f)),afactwhichrequiresanoverwritingspecication.thesemanticvariablex isusedherebecauseitwillnotrepresentthesemanticsofanygrammaticalcomplement,which ensuresthatnogrammaticalcontroliseected(seeexamples(9a,b)).thisisanexampleofa subregularityappearingwithinanexceptionalspecication. Theclassesforthetwovariantsofeasyadjectiveswehavediscussedhavethemselvesonecluster ofpropertiesincommon:theybothlicensetheoptionalpp-forphraseseeninprecedingexamples. Tofurtherreduceredundancy,wedenein(13)theclassFOR-EXPERIENCER,fromwhichthe 7AdditionalmembersofthisIT-SUBJclassincludeessential,necessary,sad,silly,andillegal. 9

twoclassesin(14-15)alsoinherit. (13)FOR-EXPERIENCER (14)IT-EASY Superclasses Complements PP-for-Features PP-for-Oblig PP-for-Role PP-for (CategoryPreposition)(Lexical{) No(PFormFor) (15)SLASH-EASY XComp-Features(VFormInnitivalGerund) It-Subj,For-Experiencer classblocksinheritanceofthesubject'sthematicroleassignment(thedefaultvaluehavingbeen nocontrollerisspecied,inkeepingwithremarkson(5).ontheotherhand,theslash-easy Asexpected,theIT-EASYclasseasesonerestrictionontheverbalcomplement;notetoothat Superclasses Complements Subject-Role XComp-Subj-SemanticsPP-For-Semantics Slash-Comp,For-Experiencer relationship(inheritedfromslash-compandultimatelyfromcontrol)sothatthepp-for speciedintheincompleteclassfromwhichcontrolinherits),andaltersthecontrol none representsasubregularitywithinasubregularity(cf.slash-comp). aretwofurtherexamplesofthewayinwhichdefaultoverwritingisemployed;notethatthelatter phraseratherthanthesubjectofeasyisinterpretedasthesubjectofthevpcomplement.these alongwithanexplicitdenitionoftheclassadjective,providedhereforclarityin(16-17),we canintroducethe(sparse)lexicalentriesforthetwovariantsofeasyemployedin(1a,b),asgiven in(17,18) Withreasonableassumptionsaboutthedenitionsofotherrelevantclassesinthehierarchy, (16)ADJECTIVE (17)easy-1a SuperclassesMajor Features SuperclassesAdjective,Slash-Easy Semanticseasy Spelling Phonology/izi/ \easy" (CategoryAdjective)(Predicative+{) Pairsofsparselexicalentrieslikethosein(17,18)arerelatedbyalexicalrulewhichwelabel (18)easy-1b SuperclassesAdjective,It-Easy Semanticseasy Spelling Phonology/izi/ \easy" 10

FOR-EXPERIENCER IT-SUBJCONTROL QQQQQQQQQs XXXXXXXXXXXXXXXXXXXXXXXXXz +QQQQQQQQs? SLASH-COMP IT-EASY 9? easy-1b SLASH-EASY Figure2:Thestructureofwordclassesdirectlyinvolvedinthedenitionofcomplexadjectival easy-1a?????? ADJECTIVE lexicalentries. LR-EASY,andwhichsimplystatesthatforeachmemberoftheclassIT-EASYthereexistsa willofcoursebequitedistinct,asneededtoensurethedierencesindistributionthatwehave correspondinglexicalentrybelongingtotheclassslash-easy,witheverythingbutthesuperclassespropertyidenticalinthetwo(sparse)entries. Onceeachof(17)and(18)areeshedouttoincludealloftheirinheritedproperties,they LE2-Classes{IT-EASY=LE1-Classes{SLASH-EASY LR-EASYlexicalrule described.figure2summarizestheinheritancerelationshipsthusfar. lexicalspecicationssuggestedonmorefamiliarelementsofgrammaticalanalysis,viz.phrases, Thepurposeofthissectionisprimarilyillustrative wewouldliketodemonstratetheeectofthe 4AnExampleAnalysis parsetrees,andpredicatelogicrepresentations. complements,inthiscasethepp-forphraseandthexcomp.thisclassofadjectivesalsohas thesemanticsofeasy-slashadjectivesforthesubject'sdenotation.toconservespaceinthe individualandastateofaairsistreatedasanormalcaseoflexicallyinheritedsemantics,i.e.one inwhichtherelationdenotedhasanargumentplaceforthedenotationsofeachoftherole-playing asubjectamongitscomplements,butitbearsnorole(aswordclassslash-easyspecies), becausethisisaraisingconstruction.forthisreason,thereisnoargumentplacereservedin diagramsbelow,relationswillbespeciednotusingthekeyword-codingshowninwordclassand lexicalentryspecications(above),butratherinthemorefamiliarorder-coding. Thesemanticsoftheeasy-SLASHconstruction,whichtreatseasyasarelationbetweenan 11

eect,weincludeheresomewhatelaborateanalyticalsketchesofthecomplexadjectivalphrase easytogetmarytohirein(19): Tobegin,wenotethatthesparselexicalentryfortheSLASH-EASYversionofeasymaybelled outtoamuchricherstructureifinheritedpropertiesarenotedexplicitly: Inordertomakenotonlythesemanticsbutalsothesyntaxsomewhatclearerinitsintended (19)TomiseasytogetMarytohire. easy-1a Complements PP-for-Features PP-for-Oblig PP-for-Role PP-for-Semantics XComp-Features No(PFormFor) PP-for,Subject,XComp (CategoryPreposition)(Lexical{) (CategoryVerb)(Complete{)(Lexical{) (CategoryAdjective)(Predicative+{) (SLASH(CategoryNoun)(Complete+) (NFormNormal)(Predicative{) Spelling XComp-Subj-SemanticsPP-For-Semantics XComp-Oblig XComp-Semantics XComp-Role Subject-Role Yes State-of-Aairs none XComp-Semantics (CaseAccusative)) Phonology \easy" /izi/(semanticssubject-semantics)) ThefeaturesnotedabovewerespeciedbythelexicalentrytogetherwiththeclassesADJEC- propertieswouldbeinheritedfromincomplete,butforbrevitythesearenotlisted.(of TIVE,SLASH-EASY,SLASH-COMP,FOR-EXPERIENCERandCONTROL.Furthersubject coursemanyotherproperties,includinge.g.,gradationpropertiesandtheapplicabilityoflexical ruleshavelikewisebeensuppressedintheinterestofclarityinpresentation.)thislexicaldescriptiontranslatesfairlydirectly(withsomefurthersimplicationsandabbreviations)intoafeature structureofthesortusedbyhpsggrammars: 12

264 syn.loc.head:adj sem:easy(1;^2) syn.loc.subcat: stem:easy2 64 subj: pp-for:syn:pp-for xcomp:2 syn:np-nom sem:3 sem:1 6 4 syn:vp-inf sem:2 subject.sem:1 slash:syn:np-acc sem:3 3 75 33 lexicallyspeciedandwhichsimplifysubsequent(grammatical)processing.thecoindexingofthe valuewiththesubject'ssemantics,ontheotherhand,derivesultimatelyfromslash-comp. xcomp'ssubjectwiththepp-foriseectedintheslash-easywordclass,andthesemanticcoindexingseenaboveisjustaconsequenceofthat.thecoindexingofthexcomp'sslash'ssemantics Wewouldliketodrawattentiontotwosemanticcoindexingsinthestructure,whichareboth 75 75 nodeisalwaystobeidentiedwiththesemanticsofaheadinaheadcomplementcombination. ThefactthattheslashvalueofthemotherstructureisemptyfollowsfromtheBindingInheritancePrinciple,whichstatesthatslashvaluesarecollectedgoingupatree unlessahead HPSGprinciples,sothatnothingisspecied,e.g.,ontherulewhichlicenseshead-complement VP/NP.Theverysparsespecicationofthemotherphrase'sfeaturesis,infact,solelyforpurposesoflegibility alloftheinformationspeciedonthemothernodemaybederivedfromgeneraticsfollowsfromthehpsgsemanticsprinciple,whichstatesthatthesemanticsofaphrasal combinations.thefactthatthesemanticsattributeisidentiedwiththesubcategorizer'sseman- InFigure3weexaminethecombinationofatokenfromthisclassofeasyadjectivesanda categorizationrequirement.theidenticationofthefeaturestructurelabeled7,whichisjust subcategorizesforanelementcontainingaslashvalue,inwhichcasetheslashsatisesthesub- therepresentationofthephrasalnodedominatingtogetmarytohire,withoneoftheadjective's subcategorizationspecications,thatlabeled6,isjustaconditionfortheapplicabilityofthe head-complementrule,notanadditionalspecication.ofcourse,thephrasalnodeismassively underspeciedhere,butthesuppressedinformationispredictable,notmerelyhidden. furthercomment,thatislargelybecausethelexiconhasprovidedawealthofrichlystructured thepropertiesofthephrasalcombinationofthisfairlyintricatesyntacticstructurerequireno representation.thiswouldhardlybefeasibleintheabsenceofecientandsophisticatedlexical representationmechanisms. ThisisanintriguingaspectofHPSG,butwedwellonithereforself-servingpurposes.If easyrelationitself.thisisexactlywhatiswantedsemanticallyofaraisingconstruction. argumentpositionoftheverbhire.thistakesplaceeventhoughthesubjectplaysnoroleinthe Figure4.NoteinparticularthatbecausetheslashsemanticsontheVPphraseisidentiedwith theslashsemanticsonthesubcategorized-forvp,whichinturnisidentifedwiththesemantics ofthesubjectforeasy,theresultantphrasewillbinditssubjecttothedeeplyembeddedobject Tocompletethisillustration,wespellouttheeectsofunicationonthestructureabovein 13

24sem:5 Adj AdjP slash:;35;where6=7 easy QQQQQQQQ 264 togetmarytohiret SVP/NP SSSSS sem:5easy(1;^2) stem:easy S comps: 2 64xcomp:6264subj:hsem:1i pp-for:hsem:1i subj: hsem:3i sem:2 slash.sem:3375 3 75 3 75 7 264sem:get(x;m; slash.sem:4 ^hire(m;4)) 375 Figure3:ThecombinationofcomplexadjectiveandslashedVPcomplement. 14

264stem:easy comps:hsubj:hsem:3t4ii sem.logic:5easy(x;^get(x;m; Adj^hire(m;T;3t4)) 375 Adj easy SSSSS SVP/NP SSSSS subjectofeasyisstillsemanticallycoindexedwiththemissingvpobject. 5ExtensionsandLexicalMaintenance Figure4:TheresultofcombiningcomplexadjectiveandslashedVPcomplement.Notethatthe togetmarytohirets Thestructuredlexiconaimsideallyataredundancy-freespecicationofalllexicalproperties,and indeed,itachievesthislargelythroughtheuseofinheritance.whilewedoseescienticparsimony asanendinitself,weseetwofurtheradvantagesintheemploymentofthestructuredlexicon,one value,andthatisbecauseastructuredlexiconismoreeasilymaintainedandextendedthan scienticandonepractical.thescienticadvantageofthestructuredlexiconisthatitidenties anonstructuredone.thisadvantagederivesimmediatelyfromthecharacteristicthatlexical andproudian,1987). signicantclassesinthelanguage.inafeaturesystemwithapproximately30atomicfeatures thatweneverseeneedtodistinguish1030classesofitems.infactwedistinguishapproximately 300lexicalclassesinHP-NL,alargesystemwithverybroadgrammaticalcoverage(seeNerbonne (includingsemantics),eachofwhichrangesoverapproximately10values,itiscertainlystriking easierinsystemswithstructuredlexiconstoexperimentwithgrammaticaldescription. propertiesarenormallyspeciedonlyonce.modicationstendthentobeminimal,andextensions lessfrightening.theultimatescienticbenetthismaybringderivesfromthefactthatitisthen VPcomplements tonounswithsimilarsubcategorizations,totheadjectivalspecierstooand extended.weexaminethereforeextensionstotheanalysisaboveofadjectiveswhichgovern Butthepracticaladvantageofthestructuredlexiconmayultimatelyalsobeofscientic enough,andtoadjectiveswhichgovernscomplementsratherthanvpcomplements. 5.1Pleasurenouns Adjectiveslikeeasyhavebeenthemostwidelystudiedgroupoflexicaltypesthatpopulatethe classesintroducedintheanalysisabove,buttheydonothaveexclusiveclaimtothoseclasses. Thefollowingsectionisanattempttobuttresstheclaimthatstructuredlexiconsareeasily LasnikandFiengo(1974:568)observedthattheEnglishlexiconalsocontainsagroupofnouns 15

withsimilarproperties,asillustratedin(20-21), (20)a.Nureyevisapleasuretowatch. b.thiscourseisabreezetopass. c.veniceisadelighttovisit. (21)a.ItisapleasuretowatchNureyev. b.itisabreezetopassthiscourse. c.itisadelighttovisitvenice. Liketheadjectivesdiscussedabove,nounssuchaspleasurehavetwovariants,onewhich appearswithanordinarynpsubjectandaninnitivalcomplementcontainingannpgap;and onewhichselectsanexpletiveitsubjectandaninnitivalcomplementwithnogap.giventhe wordclassdenitionsdevelopedonthestrengthoftheadjectivalexamples,anobviousanalysis ofthenominalexamplessuggestsitself:pleasure,likepleasant,hasonelexicalentrybelongingto theslash-easyclass,andasecondentrythatinheritsfromtheit-easyclass.the(sparse) descriptionsofbothentriesaregivenin(22-23),paralleltothoseforeasygivenin(17-18)above, thesalientdierencebeingthatthenounentriesinheritfromtheclasscommon-nounwherethe adjectiveentriesinheritedfromtheadjectiveclass.8 (22)pleasure-1a SuperclassesCommon-Noun,Slash-Easy Spelling \pleasure" Semantics.Predpleasure Phonology /plezhr/ (23)pleasure-1b SuperclassesCommon-Noun,It-Easy Spelling \pleasure" Semantics.Predpleasure Phonology /plezhr/ HavingdeclarednounslikepleasuretohaveentriesthataremembersofSLASH-EASYand IT-EASY,nothingmoreneedstobesaidinordertocapturethesyntacticrelationshipbetween thesetwoformsofpleasure.thelexicalruleweproposedearliertolinkpairsofadjectiveslikethe twovariantsofeasyisdenedasaregularityholdingbetweenthetwoclassesslash-easyand IT-EASY,makingnomentionoftheclassADJECTIVEinitsformulation.Henceitalsoserves tolinkthepairofnounentriesin(22-23). Somefurtherexplanationneedstobeprovidedaboutthesemanticsofthisclassofnouns, sincethenounsdoseemsemanticallyanomalousevenifweshallmaintainthatalloftheapparent anomalyultimatelystemsfromtheirhavingasubject andthusbeingavailableforcontrol(by beandotherraisingverbs).ingeneralacommonnounisinterpretedasarelationbetweena themeargumentandthedenotationofitscomplements,ifthereareany.forexample,friendis interpretedasarelationbetweenathemeargumentandthedenotationofthecomplementpp- OFphrase.Werefertothethemeargumentoftherelationdenotedbythecommonnounasits denotation.anapparentpeculiarityofnounssuchaspleasureisthatthereappearstobeno denotationofthenounintheusualsense,e.g.,in(20a).atissueiswhetherthereisanytheme argumentpositionforthe\pleasure"intherelationdenotedbypleasure.i.e.,doespleasuredenote thesametwo-placerelationbetweenindividualsandstatesofaairsthatpleasantdoes,oristhere athirdargumentpositioninpleasurewhichisoccupiedbyan(abstract)\pleasure"individual? Thesuspicionthatnodenotationisinvolvedlikelystemsfromourintuitionthatwedonot 8Othernounsinthisclassincludedisappointment,ordeal,challenge,joy,inspirationandprivilege. 16

noun(phrase)isusedpredicatively,muchasmanynounphrasesareaftertheverbbe.compare Tomisalinguist. oldtopicsemantically(cf.thedenitionofbeinmontague,1973,p.261),therehasbeenessentially morethanwewouldifwehadusedpleasantintheplaceofapleasure.nowthissuggeststhatthe seemtorefertoanobjectwhichisapleasureinutteringeither(20a)or(21a),atleastnotany nosuccessfulattempttotreatpredicativenounsasiftheyhadnodenotation.anyattemptto dososeemstorunafoulofthestandard(iflimited)determinationandadjectivalmodication duplicationasemanticanalysiswouldincurifpredicativenominalshadnodenotation. foundinphrasessuchasnogreatpleasuretowatch;atleastsuchexamplespointouttheinevitable Thisdoesnothelpagreatdeal,however.EventhoughtheanalysisofpredicativeNP'sisan whichobtainsjustincaseeisthepleasurexhasincases.itshouldofcoursealsoturnout thatthisrelationforsomeeholdsipleasant(for:x;soa:y),butwewillnotbeconcerned withshowingthathere.eprovidesadenotationwhichissubjecttodetermination(no)and (intersective)adjectivalmodication(great).underthisanalysis,apleasuretowatchandno pleasuretowatchdenotequantifers,i.e.,ineachcaseasetofpropertiesofpleasures(e'sfrom Wethereforeinterpretpleasureasathree-placerelation betrueorfalse forthatitmustbepairedwithaproperty.inthesecases,therelevantproperty above).ofcourse,aquantierdoesnotbyitselfrepresentaproposition,somethingwhichcould pleasure(theme:e;for:x;soa:s) Wethereforepostulatethatthepredicatebeinthesesentencesdenotestheuniversalproperty.9 semanticswhichthegeneralschemepredicts arelationbetweenathemeandthedenotations incasethereisapleasureoftherelevantkind(andmutatismutandisforthenegativeexistentials). isalwaystheuniversal(existence)property;i.e.utterancesofsentencessuchas(20a)aretruejust ofothercomplements.forthisreason,thewordclassesforpleasurenounsmakenospecial stipulationsaboutsemantics. structurestohighlightthesemanticallyrelevantparts.) andsemanticsprocessingofthewordpleasure.therststructurerepresentsthememberofthe SLASH-EASYclass,andthesecondthememberoftheIT-EASYclass.(Wehavesimpliedthe Whatisstrikingaboutthisproposalisthatitassignsthecommonnounpleasureexactlythe Wethereforederivefeaturestructuressuchasthefollowing,whichareusedinthesyntax 264subcat:264subj:hsem:3i stem:\pleasure" sem.logic:pleasure(e;1;^2) pp-for:hsem:1i xcomp:264subj:hsem:1i i.e.,thatthesubjectoftheverbbeisnotlinkedtoanyargumentpositionintherelationdenotedbythecontrolled relationsinsituationtheory(cf.section2undersubcategorization).note,however,theoneexceptionalaspect, Instead,weallowbetodenotetheidentityrelation,whichholdsofasingleargumentjustincasethereissomewayof llinginthemissingargument i.e.incasetherstexists.thisfollowsfromthegeneraltreatmentofunsaturated complement(inthiscase,pleasure). 9Infact,wedonotstipulateapeculiarsemanticsfortheraisingverbs(suchasbe)whichareinvolvedhere. sem:"logic:2 slash:3#375 3 75 3 75 17

264 stem:\pleasure" sem.logic:pleasure(e;1;^2) comps:264subj:np-it pp-for:hsem:1i xcomp:"subject:hsem:1i e.g.,bytheverbbe onlyunsaturatedphrasesaresubjecttocontrol;(ii)theirinabilitytofunction apropertytheyinherentnallyfromincomplete,intheonecasethroughcontrol,it- SUBJandIT-EASY;andintheotherfromCONTROL,SLASH-COMPandSLASH-EASY.Itis thisproperty,sharedbythenp'stheygiveriseto,whichexplains(i)theirabilitytobecontrolled Ontheotherhand,thenounclassesareexceptionalinthatthenounsinvolvedhavesubjects sem:2 #375 3 75 innormalnp's,e.g.,inthesubjectpositionofanyintransitiveverb;andnally(iii)thefactthat theycanstandinconstructionwiththemainverbbewithoutbeingassertedtobeidenticaltoits subject. entriesfor\pleasure"alsopredictthegrammaticalityjudgmentsseenin(24),analogoustothe examplesgivenaboveforadjectives,andbasedonthedenitionsgivenfortheit-easyand SLASH-EASYwordclasses.10 Weturnnowtofurtherpointsonthesyntaxofthepleasurenouns.Thetwodenitionsof (24)a.Nureyevisapleasureforustowatch. f.itisarealpleasureforusforourparentstowatchnureyev. e.forus,itisarealpleasureforourparentstowatchnureyev. g.*nureyevisapleasurewatching. d.*forus,nureyevisarealpleasureforourparentstowatch. c.forus,nureyevisarealpleasuretowatch. h.itisapleasurewatchingnureyev. b.itisapleasureforustowatchnureyev. and\pleasure",aremorphologicallyrelated.wedonotoerhereaproposalforcapturingnonproductiveregularitiesofthiskind,thoughsomeextensionofthelexicalrulemechanismmightserve,anextensionthatwould dependheavilyontheabilitytospecifynegativeexceptionstolexicalrules,givenexampleslikethefollowing. classes,wemightexpecttondnounsaswellthatbelongtotheothertwoclasses,it-subj andslash-comp.suchinstancesarefoundinenglish,asillustratedforit-subjnounsbythe 10Nothingwehavesaidsofarcapturesthefactthatsomepairsofmembersofthesetwoclasses,like\pleasant" (ii)*itisadicultytohirebill. (i)itisdiculttohirebill. Recallingfurtherthattheadjectiveswelookedatabovefellintonottwobutfourdistinct (iii)*billisadicultytohire. (iv)itisimpossibletoworkwithbill. (vi)*billisanimpossibilitytoworkwith. (v)*itisanimpossibilitytoworkwithbill. 18

examplesin(25),andforslash-compnounsbythosein(26),drawnfromlasnikandfiengo.11 (26)a.Thisroomisapigstytobehold. (25)a.ItwouldbeamistaketoreBill. d.*billwasashocktondhere. b.itwasashocktondbillhere. c.*itisapigstytobeholdthisroom. d.*itisamarveltowatchnureyev. b.nureyevisamarveltowatch. c.*billwouldbeamistaketore. theit-subjclass(togetherwithitssuperclasses);andlikethedierencesbetweenpleasureand easy,theirdierencesresultfrommistakebeingamemberofthecommon-nounclasswhile andit-easy,therulecorrectlydoesnotpredicttheexistenceofsimilaralternateentriesfor pleasure(andthetwovariantsofeasy)isdenedtolinkmembersofthetwoclassesslash-easy possibleinheritsfromtheadjectiveclass.sincethelexicalrulerelatingthetwovariantsof nounslikemistakeandpigsty. Thenounmistakeandtheadjectivepossiblehaveincommonjustthosepropertiesspeciedby inheritanceandlexicalruleproducethedesiredresultsfornounswithoutrequiringthatanything beaddedtotheanalysismotivatedfromdataonadjectivesandverbs. InteractionwithLexicalRules Giventhatthedomainoflexicalrulesisalwaysoneormorewordclasses,andthattheLR- IntrapositionruleisdenedontheIT-SUBJclass,wepredictthegrammaticalityofthefollowing exampleswithpleasurenouns,sincetheyalsohaveentriesbelongingtotheit-subjclass,and shouldbeexpectedtoconformtothelr-intrapositionrule.hereagain,thecombineddevicesof (27)a.(Forme)tostayanotherdaywouldbearealpleasure. Todrivehomeourcentralpointabouttheexpressiveandpredictivepowerofinheritancein 5.2Tooandenough d.itmightbeadisappointmentforyoutovisitvenicenow. c.tovisitvenicenowmightbeadisappointmentforyou. b.itwouldbearealpleasure(forme)tostayanotherday. COMPnounsincludebeautyandterror. propertieslikethosewehavealreadyseen.jackendo(1972,p.227)noticedthatthetwowords tooandenoughalsoappearinconstructionswithaninnitivalcomplementthatcontainsannp lexicalrepresentation,weturntoathird,smallclassoflexicalentriesthatshowcomplementation 11AdditionalIT-SUBJnounsincludebattle,disgrace,error,honor,relief,shockandsurprise.OtherSLASH- 19

gap,asillustratedin(28)withexamplesdrawnfromlasnikandfiengo(1974:536).12 (28)a.Themattressisthin. thesameasadjectiveslikepretty,entrieswhicharenotrelatedvialexicalruletovariantsthat b.*themattressisthintosleepon. licenseanexpletiveitsubject. Inparticular,theexamplesin(29)suggestthattheseadverbsselectforcomplementsthatare c.themattressistoothintosleepon. (29)a.*Itistoothintosleeponthismattress. d.thefootballissoft. f.*thefootballissofttokick. g.thefootballissoftenoughtokick. orenoughcombineswithanordinaryadjective,theresultingphrase(toothinandsoftenough) exhibitcomplementationpropertiesverymuchlikethoseofprettyadjectives.bydeningthe (30),inheritingbothfromtheADVERBclassandfromtheSLASH-COMPclass;theentryfor lexicalentriesforthesetwoadverbialspeciersasmembersoftheslash-compclass,webegin toprovideanaccountforexamples(28c,g)aswellasthosein(29).theentryfortooisgivenin enoughissimilar,leavingoutofthepresentdiscussionanaccountofthelinearorderdierence b.*itissoftenoughtokickthisfootball.informally,itseemsthatwhentoo betweenthetwoadverbswithrespecttotheadjectivetheymodify. (30)\too" verydierentgrammaticalareasareundertaken.inseveralyearsofdevelopmentathewlett- SuperclassesAdverb,Slash-Comp PackardLaboratories,involvingdetailedanalysesofdozensofconstructions,thenumberofword lexiconapproach.figure5illustratesthemorecompletestructure.itisacuriousfactthatthe numberoflexicalclassesdoesnotgrowenormouslyevenwhilefairlydetailedanalysesinvolving ofslashedvpshasgrowntoapointwhereitsurelydemonstratesthevirtuesofthestructured Withtheinclusionofthisclassofadverbs,ourlexicalsubhierarchyinvolvingcomplementation Spelling Phonology/tu/ \too" thin,nottoo,istheheadofthephrasetoothintosleepon.tomotivatethenecessaryelaboration classesneverexceeded400.thismustbeduenally,nottothelexicalanalysistool,butrather ofouranalysisforthesetwoadverbs,weturntoonemoresetofdatainvolvinggappyinnitival thesyntacticheadofaphrasethatimposesconstraintsonitscomplements;andweassumethat Yetitisclearthatsomethingmoremustbesaidaboutthisconstruction,giventhatinHPSGitis parsing,referringthereadertofullaccountsgiveninpollardandsag(1987)andrelatedreferences. tothetendencyoflanguagetoreusesignicantclasses. complements,onethathasreceivedlittlestudytodate. thecomplementationspecicationsprovidedbytooarepropagateduptothephrasetoothin.13 Wehavesaidlittlehereabouthowlexicallysuppliedsubcategorizationinformationisemployedin Thisanalysisofthesetwounusualadverbshasleftbegginganimportantissueabouthow selectsforavpcomplement.butslightlymorecomplicatedexamplesquicklyrenderthisapproachuntenable. resultweregardasunacceptable. Cf.Thiscountryistoothinlypopulatedtoworryabout(wherewetakethescopeofthespeciertootobethinly populated).here,thelexicalizedformthatselectsforavpcomplementwouldhavetobetoothinlypopulated,a 13Onemightbetemptedtotryalexicalruleapproachwhichwouldtreattoothinasaderivedlexicalitemwhich 12Baltin(1987)presentsamorerecentanalysisofthese\degreecomplements." 20

FOR-EXPERIENCER IT-SUBJCONTROL QQQQQQQQQs XXXXXXXXXXXXXXXXXXXXXXXXXz +QQQQQQQQs?PPPPPPPPPPPPPPPPPPPPq? SLASH-COMP COMMON-NOUNIT-EASY 9 SSSSSSSSSSSSSSSSSw??????? pleasure-1a easy-1b SLASH-EASY pleasure-1beasy-1a ADJECTIVE ADVERB BBBBBBBBBN isduetothefactthatsignicantclassesarebeingidentiedindetailedgrammaticaldescription. ThereisalsoaversionoftoowhichinheritsfromADVERBandIT-EASYwhichisnotshown thattheoriginalhierarchyneededverylittlemodication,merelyaddition.wespeculatethatthis Figure5:Thelexicalsubhierarchyinvolvingelementswhichgovern\slashed"verbphrases.Note (sinceitwasnotdiscussed).theasymmetryisonlyapparent. 21

ExcursusonSubcategorizationTransfer Astheexamplesin(31)show,adjectiveslikeeasyappearnotonlyinpredicativeconstructions likethoseillustratedabove,butalsoasnominalmodiers. (31)Johnisaneasymantotalkto. Whiletheexamplein(31)isgood,employingtheeasywhichbelongstotheEASY-SLASH class,theexamplesin(32-33)areungrammatical.theanalysiswehaveprovidedthusfardoes notyetexplainthegrammaticalityof(31)andtheungrammaticalityof(32,33). (32)a.*Johnisaneasytotalktoman. b.*johnisaneasyman. (33)a.*JohnisaneasymantotalktoBill. b.*johnisamaneasytotalktobill. Wewillfocusonexplainingthegrammaticalityof(31),assumingthattherightsyntactic structureforthesentenceisthebinary-branchingstructuregivenin(34),whereeasyformsa constituentwithman,andwheretotalktoissistertothephraseeasyman.weadoptthebinary structurelargelybecauseitwillsimplifytheexpositionhere;itmightbeequallydefensibletohold thateasy,man,andtotalktoareallsistersofasinglephrase.14 WhatisawkwardaboutthisstructureisthattheheadnounmandoesnotbyitselfsubcategorizefortheVP/NP.15Rather,itseemsthatwheneasycombineswithman,theresultingphrase hasasubcategorizationlistwhichcontainsnotonlytheoptionalandobligatorycomplements thatmanstartedoutwith,butalsotheobligatoryvp/npcomplementandtheoptionalfor-pp controllerrequiredbyeasy.nomechanismpresentedsofarprovidesforanadjunctcombining withitsheadtoaectthesubcategorizationofthatheadoroftheresultingphrase.yetifthe phrasestructureproposedin(33)iscorrect,somekindofmergingofsubcatinformationbetween adjunctandheadmustbeprovidedfor.16 Theexamplesin(34-35)illustratethattheowofinformationfromanadjunct'slistofsubcats tothehead'smustbequiterestricted;itwouldnotdotosimplymergethecomplementslistof 14Anditisworthnotingthatthealternativeconstituentstructurewouldnotmodifytheheadrelationship,and thereforewouldnotsubstantiallyaltertheanalyticproblem thatofexplaininghowacomplementeasytotalkto canbelicensedbyanonhead. 15Atleastnotwiththeintendedreading.Thereisasuspiciouslysimilarconstruction,illustratedin(i),which mightbeexpectedtoshedsomelightontheproperanalysisof(31),butwhichhasarestrictedenoughinterpretation tosuggestthatitshouldbetreatedseparately,probablyinheritingaspecicationfromthemoregeneralconstruction exhibitedin(31). (i)a.johnisamantoadmire. b.maryisawomantoemulate. c.thisisawordtokeeponthetipofyourtongue. TheseexamplesseemtomeansomethinglikeJohnisagoodmantoadmireorMaryisagoodwomantoemulate, wherethesemanticcontributionofgoodhasbeenincorporatedintothen{vp/npconstructionin(i).totest this,considertheexamplesin(ii),wherethegoodreadingshouldleadtoananomalousinterpretation,anddoes (cf.thecorrespondingexamplesin(iii). (ii)a.?maryisapersontounderestimate. b.?sharksareanimalstotame. (iii)a.maryisaneasypersontounderestimate. b.sharksaredicultanimalstotame. Giventheconstrainedinterpretationsofexampleslikethosein(i-ii),itdoesnotseemdefensibletotreateasyman totalktoassimplythemodiereasycombiningwithmantotalkto.anysuchattemptwouldbestrainedin accountingfor(ii);inaddition,suchananalysiswouldleaveunexplainedtheungrammaticalityof*johnisaneasy man. 16Itisprobablyworthnotingthatextrapositionseemsunlikelytobegeneralizabletoallcasesinvolvingtransferablesubcats,atleastifextrapositionistobeboundeduniformly: (i).aneasymantotalktoarrivedyesterday (ii).*aneasymanarrivedyesterdaytotalkto.22

NPS Tom JJJJVP Vis JJJJNP Det an JJJJN AdjN easy BBBBN SSSS VP/NP manvto AAAA VVP/NP talk AAAA Pto PP/NP LLLL NP/NP transferhastakenplace. Figure6:Complexadjectivals\wrapped"aroundamodiednoun.NotethattheNheadofthe Nconstituentinconstructionwiththecomplexadjectivalhasnotlicensedit.Subcategorization t 23

anyadjunctwiththatoftheheadineverycase. (34)a.*aneagermantoplease (35)a.amaneagertoplease b.*afearfulmanofsnakes c.*afrightenedmanbysnakes d.*anangrymanatjohn isthatthevp/npcomplementofeasyisobligatory,whiletheppcomplementsoftheabove adjectivesareoptional.whiletherearenotmanyadjectivesagainstwhichtotestthishypothesis, theoneclearcaseofanadjectivethattakesanobligatorycomplementcountsagainsttheidea: Theaboveexamplesmightsuggestthatwhatdistinguisheseasyfromtheseotheradjectives c.amanfrightenedbysnakes d.amanangryatjohn b.amanfearfulofsnakes orlexicalentryastransferablewillbesubjecttothefollowinginformallystatedprinciple: WhileasadefaultsubcatswillbeNon-Transferable,thosesubcatswhichareidentiedbyaclass fromadjuncttohead.justassubcatscanbemarkedfortheobligatory/optionaldistinctionina classdenitionorinalexicalentry,socantheybemarkedforadistinctionwetermtransferable. Theanalysisweproposelocalizesinlexicalentriestheabilityofasubcattobetransferred (36)a.amanfondofsnakes b.*afondman TransferableSubcatPrinciple c.*afondmanofsnakes phrasewithatransferablesubcatservesasanadjunct(easy)oraspecier(too),sothatthe wordorphrase'ssubcatlistisnotuseddirectly.theintentoftheprincipleinsuchcasesisto makethetransferablesubcatapartofthehead,sothesubcategorizationprinciplewillensure Intheconstructionsstudiedhere,thisprincipleappliesincaseswherethelexicalentryor Whenatransferablesubcatonadaughterinalocalsubtreeisnotassociatedwith somesisterinthatsubtree,thesubcatbecomespartofthecorrespondingsubcatlist constituent".17 thattheinformationispropagatedtothemothernode.thisisintendedasamodicationof thesubcategorizationprinciple notethatithastheeectoflicensingakindof\discontinuous oftheheaddaughterinthatsubtree. adjunctsandspeciersdonotpasstoheads,asseenin(33)and(34)above.thisdefaultvalue wenotethatthedefaultvalueforthispropertymustbenegative,sinceingeneralsubcatsfrom thegrammaticalityofbothexamplesin(37). willbeoverriddenforthevp/npandthefor-ppsubcatsintheslash-compclass,toreect Havingintroducedthisadditionalpropertyofsubcats,thattheycanbespeciedastransferable, abitsimilarineecttofunctioncompositionincategorialgrammar(bach,1988).butinhpsgthepossibility islexicallyconstrained. thisnon-defaulttransferablepropertyforboththexcompandthefor-pp,sowheneasycombines asanadjunctwiththeheadnounman,thesetwosubcatswillbecomepartofthesubcategorization 17Theabilitytotransferasubcategorizationrequirementfromamodiertoamother(ortoahead)isperhaps MembersoftheSLASH-COMPclass,includingtherelevantlexicalentryforeasy,willinherit (37)a.Thatwasamelodioussonatatolistento. b.johnisaneasymantoplease. 24

ofman,bytheprincipleabove,andwillthenbecomepartofthesubcategorizationofthenode complement,whichmustbeincludedasanobligatorycomplementofthephraseeasyman,due tothosewhichare(head-final+).(32b)isexcludedbecauseeasyhasanobligatoryvp/np nontransferrable.licensetheincorporation.soeasymantopleasebillwillbeexcludedforthe easyman,accountingforthegrammaticalityof(31)above. totheconventionadoptedaboveaboutmergingofsubcatinformationbetweenaheadandits VP.(33b)isprobablybestexcludedonsemanticgrounds,sincethesubjectofeasytopleaseBillisan samereasonthateagermantopleaseisexcluded:nothinglicensesthepost-nominalinnitival sister.finally,(33a)isexcludedbecausetheeasywhichrequiresanunslashedvpcomplement willnotpassonitsxcompsubcattothenounitmodies,sincethatxcompis,likemostsubcats, (32a)willberuledoutbecauseofanindependentconstraintthatrestrictspre-headadjuncts expletivepronoun,thewrongsorttounifywiththeheadnounbeingmodied.ontheassumption thatanounmustservesemanticallyasthesubjectofadjectivaladjuncts,thoseadjunctsmust thiseasyrequiresanexpletiveitsubject. anoun.whatpreventstheit-easyeasyfromservingasanadjuncttoproblemisthefactthat subjectshouldgiverisetoasemanticallyill-formedexpressionwhenitappearsasanadjunctto specifysomethematicroleforthenountoplay.thusanyadjectivewhichrequiresanexpletive ysisoftheearliertoo/enoughexamples:thelexicalentriesforthesetwoadverbssimplyspecify thattheirgappyinnitivalcomplementistransferable.18 6ConclusionsandFutureDirections Thestudyofinheritanceand,moregenerally,thestudyofstructuredlexicalrepresentationsisan excitingandpromisingeld.wewouldliketousethissectiontosummarizehowweviewthis Giventhistransferablecomplementmechanism,wemaystraightforwardlycompletetheanal- 6.1Conclusions Wehavepresentedatreatmentofcomplementationwhichusesnonmontoniclexicalinheritance. \complements"attribute. work,andtosuggestdirectionsinwhichwefeelitshouldmove. theentiretreatmentturnsonthepossibilityoftherebeinggenuinemultipleinheritanceofa Thelexicalspecicationsarequitecompactandthereforebothreadilyextendibleandeasilymodied.Wepointedoutcaseswherenonmonotonic,defaultspecicationseemsmostnatural,and adjuncts.19grammaraboundsinpoorlyunderstoodareas,includingcomparatives,superlatives, systempresentedhere,nothingisinherited.mechanismswhichwarnusersaboutsuchconicts signicantaspectsofthegrammarofthe\raisingnouns,"e.g.,theircomplements,speciers,and maintainability. areuseful,butwearewaryofattemptstodecideconicts\intelligently."theyseemlikelytous toleadtocaseswhereminorchangesmayhaveremoteconsequences,whichwoulddetractfrom lymessyorpoorlyunderstoodarea.toinsistonthispointsomewhat,letusnotethatweomitted Weadoptaskepticalapproachtoinheritanceconict.Ifthereareinheritanceconictsinthe adverbials,internalnpsyntaxandthe\specializedgrammars"foundindates,places,andtechnicalvocabulary.alloftheseareascanbenetfromtheapplicationofatoolforcomplexlexical description. 18Thisleavesmuchtobesaidaboutthelexicalpropertiesoftooandenough,butmoredetailedanalysisatthis Wedonotfeelthatwehaveoverstatedthecaseforstructuredlexiconsbychoosingaparticular- arene.sallywasapleasureoftherarestkindtoworkwith pointwouldtakeustoofaraeld;itisclearenoughthat,whatevertheirotherproperties,thesetwoadverbsshare with;relativeclausesareimpossiblesallyisapleasure*[thatisreal]toworkwith;andsomenominalcomplements complementationpropertieswiththeadjectivesandnounsstudiedhere. 19Forexample,for\pleasure"nouns,someadjectivesareokay,butnotall(areal/*competentpleasuretowork 25

6.2HypothesesorTools? Theconclusionsabovemaybereadasapleafortheemploymentofanimportanttoolincomputationallinguistics,and,indeed,weseetheprimarysignicanceoftheuseofstructuredlexiconsnot innewexpressivepowerwhichtheybringtonaturallanguageprocessingordescription(thereis perhapsnone),butratherintheincreasedeaseandreliabilitywithwhichtheyallowoldhypotheses tobeformulatedandputtouse. Brachman(1983,p.35)summarizesthedominantviewofinheritanceinknowledgerepresentation:Eventhoughmuchhasbeenmadeinthepastofthesignicanceofinheritanceinsemanticnets,noonehasbeenabletoshowthatitmakesanydierenceintheexpressive powerofthesystemthatadvertisesit...itisstrictlyimplementational. Giventhisauthorityonthetechnicalside,itmaybesurprisingtohearmoreapplicationorientedusersofinheritancemechanismshedgingatallonwhetherthereisanyscienticsignicancetotheproposalhere.Butthereisatleastapotentialcandidate:lexicalrulesmaydistinguish inheritedfromspeciedinformation. Inexpressingtherelationshipsbetweenmembersoftwosetsoflexicalentries,wemakecrucial useofthedistinctionbetweenidiosyncraticallyspeciedinformation(whichappearsinasparse (non-redundant)lexicalentry)andinheritedinformation.wehaveadoptedheretherestrictive hypothesis,proposedinflickinger(1987:108),thatlexicalrulesholdforminimallyspeciedlexicalentries,withouthavingaccesstoinherited,predictableinformation.adoptingthishypothesis imposesaconstraintontheformandfunctionoflexicalruleswhichisstrong,perhapstoostrong, butonewhichallowsasimplerformulationofrulesbykeepingtoaminimumtheamountofinformationtobemanaged.onlytwokindsofinformationarerelevantforalexicalrule:theword classesthateachofthetworelatedentriesbelongto,andanyidiosyncraticpropertiesspecied byeitherlexicalentry.wenotethatiflexicalruleswereinsensitivetothedistinctionbetween idiosyncraticandpredictablepropertiesoflexicalentries,thestatementofevenasimplerulelike LR-PAST,givenearlier,wouldbemuchmoredicult.Ifthelexicalruleforpasttenseverbshad tocopewithfully-speciedentriesthatblurredthisdistinction,itwouldbediculttoexpressin therulejustwhichpropertiesoftheoneentryhadtomatchintheother,relatedentry. Forexample,theverblikeidiosyncraticallyrequiresaverbalcomplementwhichiseitherin- nitivalorgerundive,whiletheverbenjoydoesnotallowtheinnitivalform,allowingonlythe gerundiveformforitscomplement.sincealloftheinectedformsoflikeallowthesamechoice oftwopermissibleformsfortheverbalcomplement,whilealloftheinectedformsofenjoyinsist onthegerundivecomplement,thelexicalruleslikelr-pastorthesimilaroneforpresent-thirdsingularformsmustpreservetheseidiosyncracies.yetafully-speciedentryforthebaseform enjoystipulatesnotjusttheformofthecomplement,whichwouldhavetobeidenticalinthe presentthird-singularentryenjoys;thefully-speciedbaseentryforenjoyalsospeciesthatits subjectbeunmarkedfornumber,anindierencewhichcruciallymustnotbesharedbytheentry forenjoys.shortoftaggingeachattributevalueinafully-speciedentryaslocalorinherited, itisnotclearhowthelexicalruleforpresent-third-singularformscouldbeconstrainedtoensureidentityoftheverbalcomplement'svformvaluewhileignoringdierencesinthesubject's AGREEMENTvalueforthesetwoentriesforenjoy.Insharpcontrast,thisdierenceinidiosyncraticvs.inheritedinformationcanbeexploitedbylexicalruleswithoutstipulationwhenthey areconstrainedtoapplyonlytominimally-speciedentries. Itmaynotbesuperuoustoaddthat,eveniftheargumentaboveaboutdistinguishinginheritedandspeciedinformationisultimatelyfallacious,sothattheuseofinheritancewereseen purelyasatool,andnotatallasascientichypothesis,itmaynonethelessprovetobeofgreat signicance,justasmanytoolshaveadvancedareasofsciencethatnothingtodowiththeir development.thedevelopmentoflensesrevolutionizedastromony,eventhoughglassgrinding embodiednoastronomicalhypotheses. 26

6.3Emergentissuesinstructuredlexicons e.g.,informationonlexicalrulesandtheirapplicationoughttoberenderedinfeatures.perhaps lexicalentriesmustbestructuredsothatonecomponentofalexicalentriesisafeaturestructure, whileothersarenot.20 structuresdirectly.butthisdoesnotcorrespondtoourimplementation,norareweclearonhow Perhapsmoreinterestingarethemanydirectionsinwhichthisresearchmaybedeveloped.We suggestsomeoftheseinthequestionsbelow. withthetranslationfornearlyalloftheinformationinvolved,andhavethelexicondescribefeature beapromisingareaofapplication,sinceingeneral,onecanviewinectedelementsasfurther ourlexicalspecicationsaretranslatedintofeaturestructures.theoretically,wecoulddispense Caninheritancebeexploitedinthespecicationofinectionalvariation?Thisappearsto Whatarelexicalclassesandlexicalentries?ThecarefulreadernotedinSection5abovethat References specicationsofabstractlexemes(cf.evansandgazdar,1989foranintriguingproposal). leastsomelexicalrulesrelatenotmerelyapairofwordclasses,butratherentirelexicalsubstructures(involvingseveralclasses)tooneanother.canthetechniquesofinheritancebeappliedhere, sothatexceptionalelementsmaybeeasilyaccommodated? Canderivationallexicalrulesbetreatedmoresatisfactorily?Forexample,itisclearthatat [1]Bach,Emmon.1988.Categorialgrammarsastheoriesoflanguage.InRichardT.Oehrle,. [2]Baltin,Mark.1987.DegreeComplements.InGeoreyJ.HuckandAlmerindoE.Ojeda(eds.) [3]Bayer,Samuel1990.ToughMovementasFunctionComposition.InAaronHalpern(ed.) [4]Borsley,Robert.1983.AWelshagreementprocessandthestatusofVPandS.InGeraldGazdar,EwanKlein,andGeoreyPullum(eds.)Order,Concord,andConstituency.Dordrecht: representationsystem.cognitivescience,9:171-216. ForisPublications,57-74. Proceedingsofthe9thWestCoastConferenceonFormalLinguistics.Stanford:CSLI,29-42. EmmonBach,andDeirdreWheeler(eds.)CategorialGrammarsandNaturalLanguageStructures.Dordrecht:Reidel,17-34. SyntaxandSemantics20:DiscontinuousConstituency.NewYork:AcademicPress,11-26. [7]Brachman,RonaldJ.1983.WhatIS-Aisandisn't:Ananalysisoftaxonomiclinksinsemantic [6]Brachman,RonaldJ.andJamesG.Schmolze.1985.AnoverviewoftheKL-ONEknowledge [5]Borsley,Robert.1989.Subjects,complementsandspeciersinHPSG.toappear. networks.ieeecomputer,30-36. [11]Carpenter,Bob,CarlJ.Pollard,andAlexFranz.1991.Thespecicationandimplementationofconstraint-basedunicationgrammar.Proceedingsofthe31stAnnualMeetingofthe MITPress. AssociationforComputationalLinguistics. [10]Bresnan,Joan(ed.)1982.TheMentalRepresentationofGrammaticalRelations.Cambridge: [8]Brame,Michael.1979.EssaysTowardRealisticSyntax.Seattle:NoitAmrofer. [9]Bresnan,Joan.1971.Sentencestressandsyntactictransformations.Language,47:257-281. tionalrelationships)intypedfeaturestructures withnofurtherinformation. 20KriegerandNerbonne(1991)attempttocharacterizealllexicalinformation(includinginectionalandderiva- 27

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[33]Jacobson,Pauline.1987.PhraseStructure,GrammaticalRelations,andDiscontinuousCon- [32]Jacobson,Pauline.1984.ConnectivityinPhraseStructureGrammar.NaturalLanguageand [35]Johnson,Mark.1988.AttributeValueLogicandtheTheoryofGrammar.Stanford:CSLI. [34]Jacobson,Pauline.1990.RaisingasFunctionComposition.LinguisticsandPhilosophy, LinguisticTheory,1:535-581. [36]Jones,Charles.1990.Decapitation(ofsomeso-called\Null-OperatorConstructions").In stituents.georeyj.huckandalmerindoe.ojeda(eds.)syntaxandsemantics20:dis- continuousconstituency.newyork:academicpress,27-70. 13(4):423-476. AaronHalpern(ed.)Proceedingsofthe9thWestCoastConferenceonFormalLinguistics. [37]Kaplan,RonaldandJoanBresnan.1982.Lexical-FunctionalGrammar:Aformalsystemfor [38]Krieger,Hans-Ulrich,andJohnNerbonne.1991.Feature-BasedInheritanceNetworksfor grammaticalrepresentation.injoanbresnan(ed.)thementalrepresentationofgrammaticalrelations.cambridge:mitpress,173-281. Stanford:CSLI,317-30. [39]Lasnik,HowardandRobertFiengo.1974.Complementobjectdeletion,LinguisticInquiry, [40]Maling,JoanandAnnieZaenen.1982.AphrasestructureaccountofScandinavianextraction BriscoeandAnneCopestake(eds.)ProceedingsoftheACQUILEXWorkshoponLexical ComputationalLexicons.DFKIResearchReport,DFKI,Saarbrucken.Toappearin:Ted [41]Miller,GeorgeandNoamChomsky.1963.FinitaryModelsofLanguageUsers.InR.D.Luce, Inheritance.Cambridge,UK. R.BushandE.Galanter(eds.)HandbookofMathematicalPsychologyVol.II.NewYork:Wiley, phenomena.inpaulinejacobsonandgeoreyk.pullum(eds.)thenatureofsyntactic Representation.Dordrecht:Reidel,229-282. 5:535-571. [43]Nanni,DeborahL.1980.Onthesurfacesyntaxofconstructionswitheasy-typeadjectives. [42]Montague,Richard.1973.ThepropertreatmentofquanticationinordinaryEnglish,in JaakkoHintikka,JuliusMoravcsik,andPatrickSuppes(eds.)ApproachestoNaturalLanguage.Dordrecht:Reidel. 419-492. [45]Pollard,Carl.1984.HeadGrammars,GeneralizedPhraseStructureGrammars,andNatural [46]Pollard,Carl.1985.Phrasestructuregrammarwithoutmetarules.InProceedingsofthe4th [44]Nerbonne,JohnandDerekProudian.1987.TheHP-NLsystem.Technicalreport,Hewlett- PackardLabs. Language.Stanforddoctoraldissertation. AnnualMeetingoftheWestCoastConferneceonFormalLinguistics. Language,56:568-81. [47]Pollard,Carl.1988.Categorialgrammarandphrasestructuregrammar:Anexcursiononthe [48]Pollard,Carl.1989.Thesyntax-semanticsinterfaceinaunication-basedphrasestructure TechnischeUniversitatBerlin,22-24.Feb1989,167-184.KITFAST,TechnischeUniversitat Berlin. ofthesyntax-semanticsinterface:proceedingsoftheworkshop\gpsgandsemantics", syntax-semanticsfrontier.inrichardt.oehrle,emmonbach,anddeidrewheeler(eds.) grammar.instephanbusemann,christahauenschild,andcarlaumbach(eds.)views CategorialGrammarsandNaturalLanguageStructures.Dordrecht:Reidel,391-416. 29

[51]Pollard,CarlandIvanSag.1991.Aninformation-basedtheoryofsyntaxandsemantics, [50]Pollard,CarlandIvanSag.1988.Aninformation-basedtheoryofagreement.InDiana [49]Pollard,CarlandIvanSag.1987.AnInformation-BasedTheoryofSyntaxandSemantics, Brentari,GaryLarson,andLynnMcCleod,editors,ProceedingsfromtheParasessionon Agreement,Chicago:ChicagoLinguisticsSociety,236-257. Vol.I.Stanford:CSLI. [53]Proudian,DerekandCarlPollard.1985.Parsinghead-drivenphrasestructuregrammar.In [52]Postal,Paul.1971.Cross-overPhenomena.NewYork:Holt,Rinehart,andWinston. [54]Purdy,WilliamC.1988.ALexicalExtensionofMontagueSemantics,ReportCIS-88-1,School Proceedingsofthe25thAnnualMeetingoftheAssociationforComputationalLinguistics. ofcomputerandinformationscience,syracuseuniversity. Vol.II.unpublishedmanuscriptinpreparation. [57]Ross,JohnR.1967.ConstraintsonVariablesinSyntax.MITdoctoraldissertation. [58]Sag,IvanA.1982.Asemantictheoryof`NPmovement'dependencies.InPaulineJacobson [56]Rosenbaum,PeterS.1967.TheGrammarofEnglishComplementConstructions.Cambridge: [55]Roberts,Diana.1991.LinkingRulesinanHPSGLexicon,unpublishedMaster'sThesis, MITPress. andgeoreyk.pullum(eds.)thenatureofsyntacticrepresentation.dordrecht:reidel, CornellUniversity. [59]Schachter,Paul.1981.Lovelytolookat.LinguisticAnalysis,8:431-48. [60]Shieber,Stuart,1986.AnIntroductiontoUnication-BasedApproachestoGrammar.Stanford:CSLI. 427-466. mainbodyofthepaper. AppendixA:LexicalFundamentals IntheanalysisofadjectivesgoverningVPcomplementsthatweprovidehere,weadopttheapproachtolexicalrepresentationdevelopedinFlickinger(1987).Weprovidehereabriefsketchof theframework,limitingourdiscussiontothoseaspectswhicharerelevanttotheanalysisinthe begroupedintoclassesdenedbythosepropertiesthatarecommontoallmembersoftheclass. Bygivingaprecisecharacterizationofthesewordclasses,onecaneliminateagooddealofthe makeuseofthesewordclassestocapturegeneralizationsabouttheelementsofthelexicon,andto redundancyfoundinalexiconthatconsistedoffullyspeciedentries.putdierently,onecan entry.viewingthisinformationasasetofdiscretepropertieswhichmakeupthelexicalentry, LexicalFramework itbelongsto. makepredictionsaboutthebehavioranddistributionofalexicalitemonthebasisoftheclasses Muchoftheinformationinafullyspeciedentrywithinthelexiconisnotuniquetothatparticular relatedlexicalitemswillhaveincommonsomeofthepropertiesofthatentry.lexicalitemscan shouldonlybementionedonceinsomesingleclass,withallelementsofthelexiconthathavethis classesinordertoobtainallofitsproperties.thesewordclassesformahierarchyoverwhich propertybeingmembersofthatclass.ifso,agivenlexicalitemmayhavetobelongtomany Toavoidredundancyentirely,eachpropertyrelevanttorepresentingtheelementsofalexicon 30

complementationword control incomplete :::BBBB::: JJJJ JJJJ????@@@@ transitive completepart-of-speech :::BBBB::: individuallexicalentries.oneofthenicestaspectsofthisideaisthatitisreadilyvisualized(cf. rulesaredenedthatgoverntheinheritanceofinformationfromclasstoclass,andultimatelyto Figure7). Figure7:Asampleoflexicalclassesnearthetopofthelexicalhierarchy. :::BBBB::: hierarchy,sucientwehopetoprovethepromiseofsucharepresentation.partofthishierarchy andamongthisgroupofwordclassesisonedeningthepropertiessharedbylexicalentriesthat isdevotedtospecifyingthenumberandtypesofcomplementsthatpredicatesalloworrequire, alanguage;wewillofcourseonlypresentaveryfewoftheclassesthatwouldpopulateacomplete ofboththesyntacticandsemanticpropertiesthatcomprisethefullyeshed-outlexicalentriesof governingvpcomplementsascollectionsofattributeswithassignedvalues,weshallmakeuseof classes,orindeedfromseveralsuchclasses.thishierarchyofclassesisintendedastherepository thehierarchyofwordclassesabove,whereclassesinherittheirpropertiesfromothermoregeneral Inordertopresenttheclassdenitionsthatformallyexpressthepropertiesoftheadjectives takeasubjectandacomplementwhichissemanticallycontrolled(possiblybythesubject);we labelthisclasssimplycontrol.above,weillustratethebarestoutlinesofthetopoftheword classhierarchyforenglish,tosuggestwherethecontrolclasstsin.weprovidethecontent oflexicalitems.theforcingfunctionintheidenticationofwordclassesisourassumptionthat ofcontrollater. thebestrepresentationforlexicalinformationisoneinwhicheachnewpieceofinformation,each particularsyntacticormorphologicalproperty(orclusterofproperties)issharedbyanumber severaldistinctpropertiesrendersimpossibletheuseofasimplebranchinghierarchytorepresent theyformasetofinterconnectedhierarchies;aschomsky(1965)arguedinhisdiscussionoflexical representationinaspects(pp.79-83),theneedtocross-classifyagivenlexicalitemaccordingto Wetakeasadequatemotivationfortheexistenceofawordclassthedemonstrationthatsome Itisimportanttonotethatwordclassesdonotmerelyformasimplehierarchy,butratherthat thelexicon.apropertysharedbymorethanonelexicalitemshouldbeintroducedinawordclass distinctpropertyexhibitedbyoneormoreelementsofthelexicon,isintroducedexactlyoncein commontothoseitems,orthoselexicalitemsshouldberelatedbylexicalrule.inthesimplest 31

casewhereawordclassorlexicalentrybelongstojustonesuperclass,theinheritancerulefor howvaluesofanattributeareassignedinthewordclasshierarchyisquitestraightforward.the twoalternativestobeconsidereddependonwhetheragivenattributepermitsonlyonevalue,or multiplevalues. InheritanceofValues Thevalueassignedtoaparticularwordclass(ormember)Wforagivenattributeis determinedasfollows: a.forasingle-valuedattribute,theassignedvalueiseitherintroduceddirectlyinw,or istheoneintroducedinthemostspecicclasstowhichwbelongs.ifthereisnovalue introducedanywhereinthelinkedclassesbetweenwandtherootword-class, inclusively,novalueisassignedtowforthatattribute. b.foramultiple-valuedattribute,theassignedvaluesarethemembersoftheset consistingofalldistinctvaluesintroducedforthatattributeinwandinanyofthe classeslinkingwwiththerootword-class,inclusively.21 Incaseswhereaclassormemberbelongstomorethanonesuperclass,thepicturemightbe morecomplicated,sinceeachoftwoimmediatesuperclassesmightspecifyadierentvalueforthe samesingle-valuedattribute.onewaytoaddressthepotentialconictwouldbetodeneanother ruleofinheritancetotakeaccountofmultipleparents,arulewhichforeachattributeassigns prioritytosomeoneoftheparentclasses(seethepaperontheisscolexiconinthiscollection). Weinsteadassumethatthehierarchyisspeciedinsuchawaythateachsingle-valuedattribute ofsomegivenclassormemberwasassignedavaluebyatmostoneoftheimmediatesuperclasses (oritsparents),soconictingvaluesdonotoccur. Inadoptingthisdisciplineforinheritanceoflexicalinformation,wefollowFlickinger(1987) ratherthanacceptingthemorerigorouslydenedbutmorerestrictiverulesofinheritancedened fordatrbyevansandgazdar(1989,1990).aswillbeseeninthediscussiontofollow,we believethattheabilitytoinheritalexicalpropertyfrommorethanonepotentialsourcecanbe importantincapturingrelevantlinguisticgeneralizations.therewouldbenopointtoouruse ofmultiple-valuedattributesifwedidnotallowgenuinemultipleinheritance.weemploythe multiple-valuedattribute\complements"inordertocollectsubcategorizationinformationabout severalsubcategorized-forelementssimultaneously.initsmostnaturalform,thesingleproperty \complements"inheritsfromseveralancestorssimultaneously.22 WealsofollowFlickinger,thistimeaccompaniedbyEvansandGazdar,inassumingthatlexical attributesmaybeassigneddefaultvaluesaspartofawordclassdenition,withthosedefaults possiblybeingoverriddeninthedenitionofasubclassorlexicalentryinheritingfromthatword class.inthiswepartwayswithpollardandsag(1987)'sstrongassumptionofmonotonicityinthe inheritanceoflexicalproperties,againforreasonsthatweidentifyinthediscussiontofollow.23 Whilewordclassesandtheassociatedmechanismofnonmonotonicinheritanceprovidepowerfultoolsforrepresentingonekindofsharedinformation,thatwhichlinksacategorytoits sub-categories,adistinctformaldeviceisrequiredtolinktwomorphologicallyrelatedclassesof dierentcategories.weemploythefamiliarnotionofalexicalruletorepresentthissecondkind ofsystematic(butnotexceptionless)relationship.givenawordbelongingtotherstset,a lexicalrulepredictstheexistenceofacorrespondingwordbelongingtothesecondset,withthe dierencesandsimilaritiesbetweenthetwowordscapturedbothintheformulationoftherule, andinthedenitionsoftheclasseseachwordisamemberof. 21Weemploymultiple-valuedattributesonlywithinthelexiconinordertogathersubcategorizationspeicications.Atranslationstepconvertsthesetosets(or withmoreinformation lists)foruseinthefeaturesystem. 22TheDATRpositioncarefullydisallowsmultipleinheritanceofasinglepropertyfromtwoormoreclasses, evenwhileallowinginheritancefromvariousclassesintodierentproperties(inasinglewordclass).wend genuinemultipleinheritanceseemsuseful,evenifitmaybedispensable;cf.thetreatmentofthelexicalattribute \complements"below. 23ButseePollardandSag,1987,p.194note. 32

Weillustrateournotationforlexicalruleswithanexampleofarelativelysimpleone,the inectionalrulerelatingthebaseformsofverbswiththeirpasttenseforms.wecanexpress therelationshipbetween,say,walkandwalkedasgiveninthelr-pastrulebelow,leavingout specicsofphonologyandonlyhintingatsemantics. LR-PASTlexicalrule LR-PAST LE2-Classes{PAST=LE1-Classes{BASE LE2-Spelling =(AFFIX-EDLE1-Spelling) LE2-Phonology =::: LE2-Semantics =(PASTLE1-Semantics) Thislexicalrule,likeanyother,expressesarelationholdingbetweentwosetsoflexicalentries, therstsetrepresentedbyacanonicallexicalentryle1,andthesecondsetbyle2.therule's applicabilityisgovernedbytherelevantclassesthatle1andle2eachbelongto,withthese classesnamedinthestatementwithintherulethatrelatestheoneentry'slistofparentclasses withtheotherentry'sclasslist.havingspeciedtherangeofapplicability,eachrulethenstates theparticulardependenciesholdingbetweenpropertiesofle1andcorrespondingpropertiesof LE2.24 Wemightviewinheritancewithinahierarchyofwordclassesasatoolthateliminatesredundancyalongonedimensionwithinthelexicon,whilelexicalrulesprovidethesameservicealong anotherdimension.agivenlexicalitem,byvirtueofbeingamemberofoneormorewordclasses, sharesinheritedpropertieswithotherlexicalitemsthatbelongtothosesameclasses,butdoes notnecessarilyshareacommonmorphologicalorsemanticbase(orindeedanyofitsidiosyncratic properties)withanyofthoseotheritems.thatsamelexicalitem,byparticipatinginoneor morelexicalrules,haspropertiesincommonwithasecondsetoflexicalitems,wheretheshared propertiescruciallyincludesomeoralloftheidiosyncraticinformationwhichdistinguishesthat lexicalitemfromothersinitsclass.themembersofthissecondset,relatedbylexicalrules,all doshareasinglecommonsemanticandmorphologicalbase(exceptforsuppletions). Ofcourse,ifalexicalrulerelatestwoentriesthatbothbelongtoagivenwordclass(ashappens withtheverbalinectionrules),thosetwoentrieswillsharesomeinheritedpropertiesaswellas theidiosyncracies.however,thelexicalruleonlyestablishesjointmembershipinthatgivenclass andtherelationshipoftheidiosyncraticinformationinthetwoentries;allotherpropertiesshared bythetwoareestablishedbyinheritancewithinthewordclasshierarchy. Bothoftheseformaldevices,inheritanceandlexicalrules,servetoexpressthatwhichis commonamong(oftenoverlapping)setsoffully-speciedlexicalentries,includingpropertiesthat aremorphological,syntactic,andsemantic.intheircapacityasredundancymechanisms,thetwo devicespermitaparsimoniousrepresentationoftheexistinglexicon. LexicalContent Forconvenienceofexposition,weviewthesyntacticpropertiesoflexicalitemsasbeingoftwo kinds:oneasetoffeatures,separatedintothosewithatomicvaluesandthosewithcategoryvalues, andtheotherasetofsubcategorizationspecications,dividedintocomplements(obligatoryand optional),andadjuncts.eventhoughhpsgrepresentsbothtypesofinformation(featuresand subcategorizationspecications)uniformlyasattribute-valuepairs(asnotedabove),weshall representthemlexicallyasdistinct.wehavetwomotivationsforthis:rst,inrepresenting theinformationdierentlyfromitsnormalforminhpsgwedemonstratetheindependenceof thelexicalideaspresentedhere.weemployhpsginthegrammaticalanalysispresentedhere becauseitisausefulgrammaticalframework,andbecauseitmakesstrenuouslexicaldemands; butthelexiconframeworkdoesnotpresupposehpsg(forexample,patr-iisystemscanmake 24Weincludethisruleprimarilyinordertointroducethenotationweshalllateremploy.Wewould,however, bequitesympathetictoanalternativetreatmentoftherelationbetweenpasttenseformsanduntensedlexemes whichemployedlexicalinheritanceratherthaninectionalrulestoaccountfortherelationship.wedenythatthis sortoftreatmentcanbeextendedfrominectionaltoderivationalrules,however. 33

categories)aredrawnfroma(small)nitesetwhereeachfeaturehasalimitedsetofpossible separatedintherepresentationsoflexicalentriesusedhere. atomicvalues,25e.g.,thebinaryfeatureinverted,indicatingwhetherornotaverbcanappear useofstructuredlexicons,andnearlydo,intheformoftemplates.cf.shieber,1986,pp.54- informationthreatenstoobscurepointsaddressedbelow,sothetwokindsofinformationare astheheadofaninvertedsentence.thefeaturevform,ontheotherhand,drawsitsvalues 55.).Second,auniformfeaturenotationneededforsubcategorizationandnonsubcategorization category-valuedfeatures. fromasetcontainingamongothersbase,past,andpast-participle,torepresentthe specicationforsomesyntacticcategory.sinceanynon-emptysetoffeature-valuepairsis(by denition)enoughtospecifyacategory,anysuchsetconstitutesapossiblevalueforoneofthese morphologicalformofaverb.category-valuedfeaturestakeastheirvalueafeature-structure,a Theatomic-valuedfeaturesthatweemployinspecifyinglexicalentries(andinspecifying cationanditssemanticproperties.sincereferencetosubcategorizationpropertiesofsubcatsis excludedinspecifyingcomplementsoradjunctswithinalexicalentry(cf.pollardandsag,1987: 143-4forasimilar butnotidentical \locality"restriction),wemakeuseofafeaturecom- PLETE,quitesimilartotheSUBJfeatureproposedbyBorsley(1983),andemployedinGKPS (1985:61f)todistinguishincompletefromcompletecategories.Incompleteconstituentslack oneormoreoftheirobligatorycomplements,includingatleasttheirnalcomplement(usuallythe +]torepresentthepropertythatnoobligatoryargumentsaremissing.(completecategoriescorrespondroughlytomaximalprojectionsinanx-barframework.)todistinguishlexicalcategories fromphrasalones,weusethebinaryfeaturelexical.withthesetwofeaturescompleteand Thecontentoftheword-classCONTROL,promisedabove,ispresentedhere: (38)CONTROL Superclasses Complements Incomplete subject),andaremarked[complete{],whilecompletecategoriesaremarked[complete Eachcomplementoradjunctentry,referredtohereasasubcat,consistsofacategoryspecimachinery,whilemaintainingthefullrangeofnecessarydistinctionsamonglexicalandphrasal LEXICAL,wecanfollowPollard(1984)indispensingwiththewidelyused(andabused)X-bar categories. Asthehierarchyofwordclassessketchedaboveindicates,thisclassinheritsfromtheINCOM- XComp-Features PLETEclass(whichspeciesanobligatorysubjectcomplement),andintroducesasecondobligatorycomplementwhichisaverbphrase(notcomplete,whichwouldbeitsmaximalprojection,a XComp-Semantics (Lexical{) XComp-Subj-SemanticsSubject-Semantics XComp-Oblig XComp-Semantics XComp-Role Yes (CategoryVerb)(Complete{) sentence;andnotlexical,whichwouldbejustaverbwithoutanycomplements).itwillplaythe rolestate-of-aairs(abbreviated`soa')inrelationsdenotedbywordsinheritingfromcontrol, anditwillbesemanticallyinterpretedbythevariablexcomp-semantics.thespecicationofthe classes(cf.it-easyandslash-easybelow)inherit. semanticswilloccasionallybeomittedbelow,sincetheconventionshouldbeclear.itisthiscon- TROLclasswhichwillserveasthesuperclassfromwhichbothoftheadjectivalVPcomplement whichlikewiseplaysaroleinthenalanalysis. 25Forlinguisticdefenseofmanyoftheactualfeaturesusedhere,seeGKPS(1985) Beforeconcludingthesketchofthelexicon,weturntothelexicalrepresentationofsemantics, 34

LexicalSemantics Theuseofhierarchiesofclassesofinformation,advocatedhereasameansofrepresentationfor grammaticalinformation,isalsocommonintherepresentationofsemantichyponymyrelations, e.g.,therelationbetweenboyandchild(cf.brachmanandschmolze,1985).thusboyisa hyponym(subconcept)ofbothchildandmale,whichareinturnhyponymsofmoreabstract subcategorizationareinterdependent:subcategorizersdenoterelationsamongthedenotationsof theircomplements.montague(1973)eectivelyexploitedthisbyinterpretingmultiplaceverbsand beginningwiththeobservationfamiliarfromcategorialgrammar(bach,1988)thatsemanticsand wordsandconcepts.thismaybemodeledinthesamemultihierarchicalfashionweemployfor NLinferenceengines(Purdy,1988). grammaticalinformation.suchsemantichierarchiesmaybeofutilityinconstructingmoreecient byallowingsomesemanticinheritancetofollowsyntacticsubcategorizationlines.tobemore verbphrasesasfunctionsintothedenotationsoflesser-placeverbs.weexploittheinterdependence precise,weallowsubcategorizerstospecifynotonlythesyntaxoftheircomplements,butalsothe semanticrolethecomplementisassignedintherelationdenotedbythesubcategorizer. Weexploitaverydierentuseofsemanticinheritanceinthepresenttreatment,however, INCOMPLETE TRANSITIVE Superclasses Complements Subject-Features(Complete+)(CategoryNoun) Subject-RoleSource Incomplete Complementation Object-Features(Complete+)(CaseAccusative)(CategoryNoun) bindingofargumentstoargumentpositionsismediatedbytheorderinwhichargmentsappear. orderofarguments:r(source:x;theme:y)r(theme:y;source:x).role-codedformulasareeasily mentandextendsitbyassigningthemetoobjects. Rxy6Ryx.Theuseofexplicitrolesinsemanticrelationsaccomplishesthistaskandobviatesthe ThusINCOMPLETEassignsitssubjecttherolesource;TRANSITIVEinheritsthisroleassign- Rolesmaybeunderstoodbytheirfunctioninatomicformulas:instandardpredicatelogicthe Object-RoleTheme topicssuchasvariable-placerelationsorvariably-bindingargumentssuchasthepossessive.there isfurthermoreasubstantialbodyofworkontheso-called\linking"ofsemanticrolestosyntactic information,includingespeciallyroberts(1991)whoappliesthistheorytohpsg.(eventhough weuserole-orkeyword-codedargumentsinlexicalspecications,wewilloccasionallyrevertto order-codedrepresentationsforthepurposesofillustration.theyaremoreconcise.) readablewhentherearemanyroles,andtheuseofrolesseemsessentialinsemantictheoriesof schemediscussedabove: mechanismtoderive(specicationsfor)semanticsformultiplacesubcategorizers.instancesof thetransitiveclassareassignedthefollowingsemantics,usingthemulti-valuedinheritance Whatisimportantaboutrolesforthepresentapplicationisthatwemayexploittheinheritance \Subject-Semantics"isusedbecauseitisusefultobeabletorefertothesemanticsofagiv- Lexicalspecicationsfortheargumentstotheroleshavenotbeenshown,butthegeneralscheme shouldbeclear.thepredicatemustofcoursebeassignedbyeachindividuallexicalentry. 24pred: theme:object-semantics35 source:subject-semantics 35

toaclasstowhichalexicalruleapplies,butthatruleisnotapplicabletothisentry.26thusin respecttoparticularlexicalrules.onesuchexceptionalpropertyisthatagivenentrybelongs ExceptionstoLexicalRules thelexicalclasscontroldemonstrate. encomplement(thecontroller)incasesofgrammaticalcontrol,asthesemanticsspecicationsfor thepresentcase,adjectiveslikenecessaryandpossiblewillincludeaspartoftheirsparselexical fornecessarycanthenberepresentedasin(40). entriesthestipulationthatthelexicalrulewhichusuallyrelatesit-subjands-subjmembers doesnotapplytotheseentries.callingthatlexicalrulelr-intraposition,givenin(39),theentry lexicalentriescananddostipulateamongtheiridiosyncraticpropertiesexceptionalbehaviorwith Sincefewifanylexicalrulesprovetobecompletelyexceptionless,weassumethatindividual (39)LR-Intraposition (40)necessary-1 LR-Intrapositionlexicalrule LE2-Classes{IT-SUBJ=LE1-Classes{S-SUBJ SuperclassesAdjective,It-Subj kindoffeaturesystem.seepollardandsag(1987:209,note)foraconcurringview.27 rulescanbeincorporatedintothefeaturesystemofhpsg(i.e.,inanyexplanatoryway).they seeminexpressiblebecausetheyareakindofsecond-orderproperty.thisis,infact,exactlythe sortofinformationwhichsuggeststousthatalexiconmayhavetobemorethanaparticular Itmaybeworthnotingthatitseemsunlikelythatpropertiessuchastheapplicabilityoflexical Spelling Phonology/nEsIseri/ Lexical-Rules(LR-IntrapositionNot-Applicable) \necessary" AppendixB:RenementsandLexicalModiability Inadditiontoallowingextensionspainlessly,weexpectalexicalsystemtobeeasilymodied.This isofpracticalvaluegiventherelativelyinexactstateofpresentlinguisticknowledge.linguistic presentsectionweexamineseveralrenementsoftheanalysesaboveasameansofdemonstrating themodiabilityofstructuredlexicons.wewishtounderscoretherichnessofdetailthatdemands accommodationeveninthisonecornerofthelexicon,andwehopetoprobethelimitsofthe descriptionsareunderfrequentrevision,andlexicalsystemsmustaccommodatethis.inthe lexicalrulesinthisframework,seeflickinger1987,pp.122. sinceundergonereimplementationsincommonlisp,commonobjects,andclos.theworkreportedonhere RL,alanguagederivedfromMIT'sframerepresentationlanguage,FRL(GoldsteinandRoberts,1977).Ithas formalismwehaveadoptedforthislexicalrepresentation. wasimplementedandsawdaily(experimental)useforovertwoyears.thebasicanalysesinsection4wereall is,ofcourse,athirdvariantformostadjectivesofthiskind,onewithaninnitivalvporsasits itsubject,andonewithanormalnpsubjectandaverbalcomplementcontainingagap.there 26Foramorecompletediscussionofthetypesofexceptionalbehaviorexhibitedbylexicalentrieswithrespectto 27TheinitialimplementationofthelexiconwasreportedinFlickingeretal.(1985),andwasdoneinHP- Webeganouranalysisbypresentingtwovariantsofadjectiveslikeeasy,onewithanexpletive implementedandthoroughlytestedthroughagoodvarietyofsurroundinggrammarsandapplicationeorts.we alsosuggestanalysesinthemainbodyofthepaperthatwerenotimplementedfully,inparticularinthesection onadjectivalspecication(tooandenough)andnondenotingnominalss.isapleasuretosee. 36

predicates,includingverbslikebotherandrequire,asillustratedin(42). subject,andnoverbalcomplement,asillustratedin(41). Thisselectionforinnitivalsubjectsisapropertysharedwithotherclassesofwell-studied (41)a.TotalktoBillwouldbegreat. b.formetotalktobillwouldbegreat. Toseethattheseinnitivalsubjectsmustbelexicallylicensed,considertheexamplesin(43), (42)a.FormetotalktoBillwouldbotherMary. b.towinthisracewillrequireyourfullestcommitment. c.forbilltolosethisracewouldbegreatformary. whereatleastsomemembersoftheit-subjclasscannotappearwithsuchsubjects. SLASH-COMP,toidentifytherelevantpropertiesexhibitedbylexicalentriesfortheadjectives andverbsin(41-42). WethusdeneasubclassofINCOMPLETEherenamedS-SUBJ,similartoIT-SUBJand (43)a.*Inthenalanalysis,towinthisracewillnotbenecessary. (44)S-SUBJ b.*totalktobillispossibleonlyinthemornings. Superclasses (cf.winningthisracewillnotbenecessary.) wecalls-easyforadjectiveslikegreatanddicult,sincethese,unliketheverbs,alsopermitan optionalpp-forphrase,providedasbeforebythefor-experiencerclass. Tothisclassbelongverbslikerequireandbother,butwemustalsodeneasubclasswhich Complements Subject-features(CategoryVerb)(VFormInnitival) Incomplete (45)S-EASY SuperclassesS-Subj,For-Experiencer (Complete+{) (41),whileadjectivesoftheIT-SUBJclassdonot.Hencewearetemptedtodenethelexical rulerelatingadjectiveshavingitsubjectswiththosehavinginnitivalsubjectssothattherule taskofexcludingthoseit-subjadjectiveslikenecessaryandpossiblethatdonothaves-subj suggestingthatitmustholdbetweenthetwoclassesit-subjands-subj.thisleavesusthe holdsbetweenthetwoclassess-easyandit-easy.however,verbslikebotherandrequirewith counterparts. entriesthataremembersoftheit-subjclassshouldalsobecoveredbythissamelexicalrule, ItappearsthatingeneraladjectivesoftheIT-EASYclassalternatewithentrieslikethosein DistinctionsamongUnboundedDependencies whichshowthatsomefurtherconstraintsneedtobeplacedonthegappyverbalcomplementwhich Asecondrenementofouranalysisofeasyadjectivesismotivatedbyexampleslikethosein(46), possibleoutofniteclausesembeddedwithinthecomplementtoeasyadjectives,butisotherwise suchadjectivessubcategorizefor.informally,thegeneralizationseemstobethatextractionisnot 37

licensed.28 (46)a.BillwaseasytogetMarytohire. b.palmtreesarehardtolearntoclimb. c.ariasarefuntotrytosing. d.*billwaseasytoseethatmaryadmired. (cf.bill,it'seasytoseethatmaryadmires.) e.*palmtreesarehardtolearnthatonecanclimb. f.*ariasarefuntoinsistthatpeoplesing. Generalconstraintsimposedbytheframeworkwehaveadoptedherepreventusfromattemptingtodescribethesefactsbymakingeasyadjectivesselectforaverbalcomplementwhosehead requiresitscomplementtobenon-nite.29instead,wefollowhukariandlevine(1991),who proposethattwotypesofunboundeddependenciesmightbedistinguished,withonedependency path,markedbythenewbindingfeatureslash0,treatingnites'sasislands,whiletheordinary SLASHfeaturemarkstheusualdependencypathwhichisinsensitivetoniteSnodes.Then easyadjectivesoftheslash-easyclasswouldmorepreciselysubcategorizeforaninnitival complementthathasannpgapofthemarkedslash0varietyratherthantheusualslash.to illustrate,considerexample(46d):theslash0featurethatwould(byhypothesis)beintroduced attheextractionsitewithintheembeddedsthatmaryadmiredwillbepassedupfromthatsite byageneralprinciple,butwillstopitsascentwhenitreachesthats.assumingthattheverbsee doesnotselectforthisunusualkindofslash0complement,thesentencewillnotbeadmitted asgrammatical.incontrast,theexamplein(46a)willstillbeadmittedsincetheslash0introducedattheextractionsiteintohirewillbefaithfullypassedupbythesamebindinginheritance principleuntilitreachesthenodedominatingtogetmarytohire.nowthisvp[slash0np]is, accordingtoourproposedrenement,preciselythekindofcomplementthateasyrequires,sothe sentenceisgrammatical. Ofcourse,toproperlydefendthisadditionofSLASH0tothecollectionofbindingfeaturesfor English,wewouldliketondindependentevidenceoftheclaimthatniteS'scanserveasislands forslash.weleavethematterhereasonemeritingfurtherstudy,andrefertheinterestedreader tojacobson(1987)forasimilarsuggestiontodistinguishvariousslashattributes. PiedPiping Athirdrenementoftheanalysisgivenaboveismotivatedbyexampleslikethosein(47),where theeasyadjectiveappearsinanounphrasewithaninnitivalcomplementcontainingapied-piping construction,notaccountedforinwhatwehavesaidthusfar.30 (47)a.Maryisaneasybossforwhomtowork. b.newyorkwouldbeanawkwardcityfromwhichtoee. c.billmightbeahardpersoninwhomtoconde. Themoststraightforwardcharacterizationofphraseslikeforwhomtoworkistodescribe themasinnitivalvpscontainingarelativepronoun.sinceenglishindependentlyprohibits relativepronounsfromappearinginsituwithinaverbphrase,theonlywaysuchaphrasecanbe producedistohaveapied-pipedprepositionalphraseextractedfromthevpandsistertoit.31 Assumingthatsuchaphrasemustbeadmittedbythegrammar,wecanformallyrepresentits syntacticcategoryasshowninthefollowingdenitionforthenewclassrel-easy.whatwemake 28Jones(1990)attributestheobservationtoChomsky(1977). 29Fordiscussion,seeFlickinger,1987,pp.67;PollardandSag,1987,p.143 30Chomsky(1977)citesexampleslikethese;weappreciateAnthonyKroch'sbringingthemtoourattention. 31Amongotherdetails,thephrasestructurelinkingrulewhichwouldbenecessarytoadmitthis[VP[RELNP]! PP[RELNP];VP/NP]constructionwillalsohavetobemadeexplicitinafulleranalysisthanweprovidehere,but thatshouldnotbeproblematic.wehaveinmindasimplegeneralizationofthesententiallinkingrule,sothatno novelrulewouldberequired. 38

dieringfurtherinthattheserel-easyadjectivesdonotseemtolicenseanoptionalpp-for (linkedviaalexicalrulesimilartoonesseenabove)thattakeanunusualkindofvpcomplement, complement.thenalpropertyidentiedinthisclassisthatitsmembersaremarkedasnot explicithereistheideathatadjectivesoftheslash-easyclasshavecorrespondingmembers predicative,eectivelyrestrictingitsmemberstoattributiveadjectives.thispropertyaccounts fortheungrammaticalityoftheexamplesgivenin(49). (48)REL-EASY Superclasses Features Complements XComp-features(VFormInnitival) Control,Adjective (Predicative{) (REL(CategoryNoun)(Complete+) headedbyeasyandpleasurewouldhavetobenon-predicativeinorderforthoseheadstolicense Inbothexamplesin(49),thecomplementofthecopulaismustbepredicative,butthephrases (49)a.*Billiseasyforwhomtowork. b.*billisapleasureforwhomtowork. (NFormNormal)(Predicative{) theirvp[relnp]complements.indeed,(49b)isalsoruledoutbyanotherconstraintwhich (CaseAccusativeDative)) henceuntformembershipintherel-easyclass,sinceattemptingtoassignthemtothisclass wouldintroduceaconictofinheritedvaluesfortheattributepredicative,andsuchconicts areprohibited,aswenotedaboveinourintroductiontothegeneralframework. wenessedinourbriefintroductionofpleasurenouns,forclarityofexposition:wedescribed reninginamoredetailedaccount,sincepleasurenounsexhibitonlyafewofthepropertiesof regularcommonnouns.inparticular,itseemsclearthatthesenounsmustbepredicative,and suchnounsasbelongingtotheordinarycommon-nounclass,butthatassignmentalsoneeds 39