Phonological Effects on Non-Native Grammar: An Example Paper. John Foreman April 22, 2003

Transcription

1 Phonological Effects on Non-Native Grammar: An Example Paper by April 22, 2003

2 1. Introduction Throughout my teaching career, I have encountered many writing samples by non-native speakers of English. Among other difficulties they may have, the students frequently fail to produce the correctly inflected forms of words. Verbs may fail to be properly inflected for tense or nouns for number. Consider the following examples from a native Spanish speaker's writing. The student shows problems with realizing the ed verbal suffix, as shown in the examples below. -ed omitted (relevant verb underlined) (1) a. " we are introduce to the stages of the word-learning process." b. " the order in which words are require like the tense in speech." c. " learned words by observing how the words are use in intelligible contexts." d. "Mysteries have being (sic) solve but new ones have arose " -ed correctly applied (relevant verb underlined) (2) a. "One of the important stages is semantics, which govern (sic) the way words are interpreted." b. "Many studies have being (sic) conducted to find out " c. " provide the information when it is wanted can significantly improve " d. " because that's when the degree of meaning is applied." e. "Lying is categorized in three different degrees." f. "We are introduced to the fact that English speakers " At first glance, it may appear that the student has only a tenuous grasp of the syntactic environments requiring an ed suffixed form of the verb. The student clearly knows the correct auxiliary verbs (italicized in 1-2) to form the perfect and passive constructions in English (as schematized in 3). (3) a. HAVE + Verb-ed perfect b. BE + Verb-ed passive However, the student apparently fails to fully grasp the second requirement of these constructions that the main verb be in the past participle form, usually realized with an -ed suffix. This feeling is reinforced by the fact that some verbs such as introduce sometimes appear correctly with the ed suffix (2f) and sometimes do not (1a). In this paper, I will show that the student does in fact have mastery of all aspects of the constructions in (3). The errors in (1) are not problems of understanding the morphology or syntax but are problems of phonology. The student knows when to utilize the ed suffix, but phonological considerations may result in the deletion of the inflectional morpheme. 2

3 2. Hypothesis Why does the writer of (1) and (2) have trouble with English inflectional morphology? It is unlikely that it is due to the number of inflectional morphemes in English. Compared to numerous other languages, such as Spanish, Italian, Russian, Lakhota or Quechua, English inflectional morphology is severely limited. In English, there are at most only two forms for lexical nouns (singular or plural) and regular verbs have only four forms all using an identical set of suffixes(-, -s, -ed, -ing). Even the relatively small number of irregular verbs have at most only one additional form (-en) and are usually only irregular with respect to the ed forms of the verb. 1 By comparison, Spanish and Italian verbs come in about 50 forms, while Kivunjo, a Bantu language, can have about half a million forms for a verb (Pinker 1994). Thus, it seems unlikely that it is the sheer number of inflections which has caused the student in (1-2) difficulty with English. Furthermore, as I will show in this paper, it is also not a problem with understanding the syntactic environments in which the inflected forms are used. Instead, some other factor is at work. It has been observed that problems like those in (1) are not problems of morphology or syntax, but of phonology. Although there are only a few inflectional suffixes in English, they are frequently not very salient, because they frequently result in sequences of consonants, particularly final consonant clusters. Such clusters are relatively rare across languages and thus pose difficulties for non-native speakers. The speakers may have difficulty both perceiving and pronouncing all of the individual consonants in such environments. As a result, the inflectional affixes may either not be heard or may be deleted in order to ease pronunciation. In fact, this loss of inflection through consonant cluster simplification is observed not only with non-native speakers but also in various dialects of English, such as African American English (Labov 1995, Green 2002 and references therein) and Chicano English (Santa Ana 1996). The prediction then is that the student is more likely to omit an inflectional suffix in cases in which the addition of a suffix results in a consonant cluster when it is attached to a word that ends in one or more consonants. For example, the ed morpheme has three allomorphs, [-t], [-d] and [-id] as illustrated below: (4) a. crashed [krqst] b. crammed [krqmd] c. glided [glajrid] picked [pikt] starved [starvd] booted [buwrid] elapsed [ lqpst] died [dajd] banded [bqnrid] The[-t] allomorph only occurs after voiceless obstruents (excluding /t/) and thus always results in the creation of a consonant cluster. The [-d] variant follows voiced sounds (excluding /d/) and also frequently produces coda consonant clusters when following voiced consonants, as in the crammed example. It can also follow vowels, however, so it 1 Of course, be has a few additional forms bringing its total to eight, while three other verbs also have irregular s forms, has, does and says. 3

4 does not always result in a consonant cluster. 2 The [-id] variant, which only follows /t/ or /d/, which are usually phonetically realized as [R], results in an extra syllable being added to verb and because of the intervening vowel does not produce a consonant cluster. If presence of final consonant clusters are playing a factor in the student's realization of the ed suffix, then the prediction is that the [-t] variant of ed should be the least salient and therefore most susceptible to being deleted, the [-d] variant should be more salient, at least when following a vowel, and less susceptible to deletion, and the [-id] variant should be the most salient and least likely to be deleted. The prediction is summarized below in (5). Prediction of increasing likeliness that ed will be deleted (5) /t/ and /d/ verbs verbs ending in vowels verbs ending in other consonants If, however, it is merely the case that the student has not fully mastered the syntactic frameworks like those in (3), then the phonological form of the verb and issues of consonant clusters should make no difference on whether the suffix is deleted or retained. Errors of omission should fall equally and randomly across the different verb types and allomorphs. Similarly, if the phonological hypothesis is correct, irregular ed forms should also be relatively free of errors. Irregular ed forms rely mostly on vowel changes to signal grammatical differences and thus do not usually suffer problems arising from consonant clusters. For example, the differences between find and found is indicated by a very salient vowel change and does not rely on consonant clusters. Again, if the phonological hypothesis is correct, such verbal forms should be correctly produced Methodology To test the hypothesis that consonant cluster simplification is leading to the deletion of inflectional morphology within the student writing of (1), I focused on the 2 How frequently it forms a consonant cluster depends on the status of diphthongs, however. If the diphthongs consist of a vowel component and a following glide component, [aj] for example, the [-d] will almost always form a cluster. The only case where it would not form a cluster would be when it follows a verb ending in schwa. If an analysis of two vowel components is more accurate for diphthongs in English, [ai] for example, there will be many more instances in which [-d] is not part of a consonant cluster. 3 An alternative hypothesis for why irregulars are less error prone might be because they are more frequent. This issue is not addressed in the present paper, but if frequency plays a role for irregulars it should factor into realizations of regulars as well. Since, a priori there is no reason to suspect that verbs ending in /t/ or /d/ should be more common than verbs ending in other consonants, such as /k/ for example, we would expect the frequency effects to be evenly distributed across the allomorphs. They are not, however, and verbs ending in /t/ or /d/ show disproportionately fewer errors than other regular verbs. This fact seems difficult to account for in terms of frequency alone. So, while frequency may play a role, it is not the only factor at work, and the observed patterns fit well with the phonology hypothesis. 4

5 realization of the regular past participle morpheme ed in perfect and passive constructions as schematized in (3), repeated below: (3) a. HAVE + Verb-ed perfect b. BE + Verb-ed passive This particular suffix in these particular constructions were chosen for a number of reasons. First, the ed morpheme, as discussed in section 2, crucially has three allomorphs, two of which can be in a coda consonant cluster and one which cannot. In contrast, the lack of variation in the present progressive morpheme ing makes it unsuitable for testing the current hypothesis. Second, the rather restricted, but overtly marked, environments of (3) make it very clear when the suffix is correctly applied and when errors of omission have been made. The factors governing the use of the past tense ed or the plural s for example are more complex and not always overtly present in the syntax. Judging if an omission is an error in such cases can be tricky requiring guesses at the writer's intent. Third, the environments in (3), particularly the passive construction, were well represented in the available data. I went through five writing samples of the student's and counted and evaluated the perfect and passive constructions detailed in (3). There were 69 instances of these constructions involving regular past participles (those marked with ed) and an additional 38 instances involving irregular past participles (formed without the ed suffix). I tabulated each group separately. Perfect and passive constructions of the correct form AUX + Past Participle (Verb-ed for regular past participles) were counted as correct instances, while AUX + Bare Verb 4 (for regulars, Verb without ed) were counted as incorrect. Note that I did not include other (potential) instances of the ed suffix such as the past tense ed or adjectival ed. As noted above, the conditioning environments are more complex and are not always conveniently signaled by an auxiliary as the constructions in (3) are. Only the environments in (3) were considered, even other potential auxiliaries such get and got were excluded. There were five instances of conjoined past participles which were included. Of these, three of second conjuncts were irregular and all were correctly formed while one regular was correct and one incorrect. In addition to this information, I also recorded whether the regular verb root ended in /t/ or /d/, another consonant, or a vowel, assuming a vowel analysis of diphthongs. I also noted whether a vowel, consonant, or phrase boundary followed the verb to determine if this had any confounding influence. 4 In these environments, the student either gave the correct form or produced the bare form of the verb. There were not erroneous instances of other verb forms, with the exception of being which was systematically used in place of been. I judged this to be merely a spelling error or misperception that the past participle and present participle of be is identical. I do not feel it was a misanalysis that have can occasionally take an ing verb as this was never seen for any other verb. Finally, there was one instance, lead, of an irregular verb with an identical bare form and past participle form. This was counted as correct. 5

6 4. Findings Out of 107 potential past participle environments as defined above in section 3, the student had 21 errors, 19.6% of the total environments. The errors were not randomly distributed as might be expected if the errors were merely the result of incomplete mastery of the morpho-syntactic environments of (3). Instead, the errors are, as predicted, disproportionately represented in cases involving clusters. That the student has in fact internalized the morphological requirements of (3) is evidenced by the successful use of irregular past participles and past participles of regular verbs ending in /t/ or /d/. As summarized below in Table 1, of the 38 (potentially) irregular past participles, 36 were correctly inflected. 5 Even more impressively, 100% of the 23 regular /t/ /d/ verbs were correctly suffixed. Table 1. All irregulars t/d roots # correct total environments percentage correct 80.4% 94.7% 100% This indicates then that the student has mastered the morphological requirements of the perfect and passive constructions in English. The student knows that perfect have and passive be are followed by past participial verb forms, which are regularly formed via the suffixation of ed. If this were not the case, we would expect the approximately 20% error rate found in all cases to be reflected in the past participles of irregulars and /t/ /d/ verb roots. We should expect 7 or 8 errors with the irregulars and 4 or 5 errors with the /t/ /d/ roots. Instead, there were only 2 errors in total. All others are disproportionately found with the [-t] an [-d] allomorphs. The main predictions that /t/ /d/ regular verbs and irregular verbs have more salient past participles which are thus more likely to be correctly realized are borne out. What about the secondary predictions that regular verbs ending in consonants should be more susceptible to deletion of the ed suffix than vowel final verbs? Surprisingly, this prediction doesn't hold for the available data. Errors were disproportionately found with vowel final regular verbs, as summarized below in Table 2. Table 2. regular verbs t/d roots other C V # errors total environments percentage correct 27.5% 0% 36.4% 53.8% 5 Note that as discussed in Footnote 4, this does include 13 instances of been spelled <being> which were just to be correct. Even if we put these cases aside, 23 of 25 other irregulars, or 92%, were still correct, suggesting that, as predicted, irregulars are correctly inflected in part at least because they do not have the phonological difficulties (consonant clusters) of many regular verbs. 6

7 53.8% of the regular verbs ending in vowels failed to take the expected ed suffix, while only 36.4% of the consonant final verbs were incorrectly inflected. What might account for this difference? Other phonological factors, such as following consonants, cannot account for the discrepancy. One possibility is that this is simply an artifact of the relatively small sample size. There were only 13 total vowel final regular verbs present in environments that were investigated. It is highly likely that the errors were simply overrepresented in such a small number of environments. Another possible factor is that, as mentioned above, the diphthongs of English should be analyzed as vowel-consonant sequences. The ed suffix would produce a cluster then and would be just as susceptible to deletion as it would be following any other consonant. Three of the errors are following [r1], which I counted as a vowel. Perhaps for this speaker it is better analyzed as [ r]. The remaining errors follow [ou] and [i:]. If these are realized as [ow] and [ij], however, then the words could be analyzed as having a consonant cluster and could explain the deletion of the ed suffix. Whether this truthfully reflects the student's pronunciation or perception is unknown Conclusion Linguistics can help with second language learning by helping identify the patterns in student errors and determine exactly which areas of the language cause difficulties. In this example, we have seen that it was not the syntactic or morphological rules that were causing difficulties, but rather perceiving and pronouncing the effects of those rules. Having finally identified the problem, how do we assist students in progressing toward the standard English pattern? For speakers who are first learning to apply the rules in (3), it is important to present words in those environments which will help make the suffixes most salient. As seen in the data here and as suggested by Labov (1995), that environment for the -ed suffix is following words ending in /t/ or /d/. Students who have clearly mastered the rule but still lose the suffix through phonological reduction can benefit from having this made explicit to them and can then use test words such as construct to help them observe if the past participle ending should be present or not. 6 Another possibility not considered here is that, for this native Spanish speaker, word final [d] is no more salient following a vowel than following another consonant. This explanation is unsatisfactory, however, since Spanish has word final /d/ or at least [D] as in ciudad 'city,' though perhaps not in this speaker's dialect. Additionally though, the two errors made with irregular past participles were with the verbs show and know, whose past participles are formed by phonetically adding [-n]. While [d] may not occur word finally in Spanish, [n] certainly does. So, this account will not explain why [n] was left off. The diphthong/cluster hypothesis might, however. 7

8 6. References Green, Lisa J African American English: A Linguistic Introduction. Cambridge: Cambridge University Press. Labov, William Can Reading Failure Be Reversed: A Linguistic Approach to the Question, in V. L. Gadsden and D. A. Wagner, eds., Literacy Among African-American Youth: Issues in Learning, Teaching, and Schooling. Cresskill, NJ: Hampton Press Pinker, Steven The Language Instinct: How the Mind Creates Language. New York: HarperCollins. Santa Ana, Otto Sonority and Syllable Structure in Chicano English. Language Variation and Change, Data Appendix verb ends in verb followed by sequence frame correct? key are introduce to passive n C C n=no is use to passive n C C y=yes are introduce to passive n C C T/D=/t/ /d/ was use to passive n C C IRR=irregular being (been) solve but passive n C C C in Column 4=Consonant and burn by passive n C C other than /t/ or /d/ was more like(ly) use was passive n C C C in Column 5=Consonant are train to passive n C C V=Vowel are use in passive n C V.=phrase final be use as passive n C V are perceive as passive n C V is perceive as passive n C V is also introduced. passive y C. are introduced to passive y C C are introduced to passive y C C is characterized by passive y C C being processed that passive y C C was marked by passive y C C were confirmed during passive y C C are seemed to passive y C C is many times misused not passive y C C is categorized as passive y C V is described as passive y C V are also discussed in passive y C V was produced in passive y C V was imposed upon passive y C V past on. passive y C V be well explained and passive y C V is established as passive y C V is categorized in passive y C V have learned. perfect y C. has evolved to perfect y C C 8

9 have learned about perfect y C V are interpreted. passive y T/D. be decode it. passive y T/D. was tested, passive y T/D. was innovated. passive y T/D. being (been) conducted to passive y T/D C being (been) conducted to passive y T/D C is wanted can passive y T/D C was suggested that passive y T/D C was suggested that passive y T/D C were submitted to passive y T/D C is connected to passive y T/D C being (been) conducted to passive y T/D C being (been) conducted to passive y T/D C was recorded through passive y T/D C being (been) recorded that passive y T/D C is divided into passive y T/D V are invented and passive y T/D V had predicted that perfect y T/D C have recorded their perfect y T/D C have recorded the perfect y T/D C have innovated to perfect y T/D C have supported and perfect y T/D V have decided is perfect y T/D V is follow by passive n V C is follow by passive n V C are require like passive n V C was discover that passive n V C being (been) study and passive n V V were later discover and passive n V V been borrow or passive n V V or modified. passive y V. is clearly accompanied by passive y V C and modified with passive y V C be modified dramatically passive y V C modified and passive y V V is applied. passive y V. have show that perfect n IRR C are given a passive y IRR V are given a passive y IRR V are known as passive y IRR V were found in passive y IRR V was made; passive y IRR. was done where passive y IRR C was found that passive y IRR C is said to passive y IRR C have arose but perfect y IRR C 9

10 and lead vast perfect y IRR C have had many perfect y IRR C has being (been) findings x13 perfect y IRR C being (been) proven that passive y IRR C have shown that perfect y IRR C were know in passive n IRR V must of taken time perfect y IRR C and well written for passive y IRR C have had a perfect y IRR V and maybe written down passive y IRR C be written down passive y IRR C have taken long perfect y IRR C be written down passive y IRR C have gone through perfect y IRR C were not taken away passive y IRR V has being (been) proven to passive y IRR C 10