FMRI of Past Tense Processing: The Effects of Phonological Complexity and Task Difficulty

This study investigates whether L2 learners (L2ers) use the same mechanisms as those of native English speakers (NSs) for processing regular and irregular past tense forms. Intermediate-to-advanced Persian-English L2ers and NSs participated in two online experiments using Speeded Grammaticality Judgment tasks. Experiment 1 examined regular and irregular past tense forms and Experiment 2 the effect of frequency on regular past tense forms. The results of both the accuracy and reaction time data show a pattern of convergence between NSs and L2ers. Particularly, the accuracy data provide new evidence showing that L2ers converge on NSs in showing distinct processes for regular and irregular tense forms. Additionally, both groups similarly showed an anti-frequency effect for regular verbs, i.e., the frequency increased accuracy rates for low-frequency regular verbs in comparison to high-frequency ones. It is concluded that L2ers use mechanisms similar to those of NSs for processing regular and irregular past tense forms.

RULES AND SCHEMAS IN THE DEVELOPMENT AND USE OF THE ENGLISH PAST TENSE Joan L. BybeeDan I. Slobin State University of New York,University of California, BuffaloBerkeley Consistent error patterns in English past-tense forms are reported for three age groups: preschoolers, 8-10-year-olds, and adults. It is argued that, although irregular forms are rote-learned, speakers make generalizations about such forms. Such a generalization is defined as a schema which describes general phonological properties of a morphological class, and is used in organizing and accessing the lexicon. Schemas for the English past tense develop and change with age, yielding implications for both acquisitional and diachronic theory.* 1. English verbal morphology is rather restricted, compared to that of a fullfledged inflectional language, since it offers only four inflectional morphemes: the 3rd singular present, the past tense, the past participle, and the progressive. Thus it provides no opportunity to study the complex interaction between intersecting inflectional categories within a paradigm, such as person, number, mood, and tense. It does, however, provide the opportunity for a study of a different sort: although English has a demonstrably productive process of suffixation for past-tense formation, in the form of -ed, it also has many irregular verbs whose past tense is formed in some cases without suffixation, and in others with changes of vowel (or, less commonly, consonant) in the stem. These irregular verbs are relatively few in number. Bloch 1947 identifies about 200 (several of which are archaic), but thousands of verbs form their past tense by adding an allomorph of -ed. Although irregular verbs are relatively insignificant as to type frequency, the picture is quite different when token frequency is considered: these are among the most frequent verbs of the language . Of the 30 most frequent past-tense forms (Kucera & Francis 1967), 22 are irregular. The situation changes radically in the second 30 most frequent past-tense forms, where 8 are irregular. From the child learner's point of view, irregular verbs are also prominent: Slobin 1971 finds that, in 49 hours of adult speech to Roger Brown's subject Eve, between the ages of 18 and 26 months, irregular past-tense forms account for 292 of the past-tense tokens, while regular verbs comprise only 99. Thus irregular past-tense forms constitute an important core of English verbal morphology. * A number of people contributed to the research reported here, and we would like to thank them for their help. Susan Ervin-Tripp, Roger Brown, and Zell Greenberg made their spontaneous speech data available to us; Zell Greenberg tested the preschool children and analysed the results; Amy Strage and Ann Eisenberg tested the adults; Mr. B. Harris and his third-grade class at Cornell Elementary School, Albany, CA, played the 'verb game' with us; Tanya Renner, Carol Lynn Moder, and BongHee Choi helped with the statistics; and Brody Hooper let us use his verb forms and his friends. While this research was being conducted, loan Bybee held a Postdoctoral Research Training Fellowship from the Social Science Research Council. This research was also supported by the University of California Committee on Research and the Institute of Human Learning, University of California, Berkeley. 265 266LANGUAGE, VOLUME 58, NUMBER 2 (1982) The difficulty presented by these irregular verbs, both for the learner and for the linguist, is that so many different irregularities occur. Though most irregulars are characterized by a vowel change, a number of different changes occur, e.g. stick/stuck, sing/sang, keep/kept, grow/grew. In addition, some verbs add a t or d; and some have consonant changes as well, e.g. makelmade. Jespersen 1942 lists ten classes of irregular past-tense formations, and dozens of sub-classes, while Bloch comes up with twenty conjugation types. Such variety increases the difficulty of the learning task, but at the same time provides us with an opportunity to investigate the interaction of rule and rote-learning in morphology. It is clear that some rote-learning is necessary in acquiring irregular past-tense forms: the pair go/went could not be learned in any other way. What is not so clear is whether speakers must learn all irregulars by rote, or whether...

Opposing views of storage and processing of morphologically complex words (e.g., past tense) have been suggested: the dual system, whereby regular forms are not in the lexicon but are generated by rule, while irregular forms are explicitly represented; the single system, whereby regular and irregular forms are computed by a single system, using associative connections; and a system whereby phonological rules relate both regular and irregular past to present tense forms. Two reaction time experiments investigated the production of the past tense in English in response to the auditory presentation of the present tense of the verb. The first experiment addressed the methodology of presenting regulars and irregulars in blocked form as in a previous study (Jaeger et al. in Language 72:451-497, 1996). Blocked presentation results showed longer RTs for the elicitation of irregular pasts than for regular pasts; however, there were no differences between regular and irregular elicitation when the presentation was randomized, indicating that it is rules that are being primed. The second experiment tested whether the response time advantage found for blocked regular verbs in the first experiment might also extend to irregular verb forms exhibiting the same sub-regularity (e.g., sing-sang may prime ring-rang). Results showed a trend towards slower RTs when past tense forms from different sub-regularities follow one another, suggesting interference between one sub-regularity and another.

Rules, representations, and the English past tense

Purpose: This study addresses the question of whether sequential bilingual children’s past tense marking development in their second language (L2) is affected by their knowledge of temporal marking in their first language (L1). We investigated whether Cantonese-English sequential bilingual children’s knowledge of aspect markers in Cantonese (L1), along with external and internal factors, predicts their past tense marking in English (L2). Method: We examined 39 pre-school children’s production of perfective aspect markers in Cantonese and regular and irregular past tense morphemes in English using a story-retell task administered in both languages. Result: The results showed that children produced significantly more irregular past tense verbs than regular past tense verbs in English. Their English irregular past tense use, but not regular past tense use, was predicted by their knowledge of aspect markers in Cantonese. Conclusion: Findings suggest that semantic transfer between Cantonese and English might contribute to the early stages of acquiring English past tense marking. Clinically, the results could potentially lead to more informed assessment procedures and better diagnostic decision making for bilingual children.

Is language governed by formal rules or by analogy to stored exemplars? The acquisition of the English past tense has long played a central role in this debate. In the present study, children rated the acceptability of a regular and an irregular past-tense form of each of 40 novel verbs (e.g., fleeped, flept) using a 5-point scale. The novel verbs were chosen to vary continuously along the orthogonal dimensions of (a) similarity to existing regular forms and (b) similarity to existing irregular forms. A developmental progression was observed whereby the acceptability of novel regulars was shown to increase as a function of similarity to existing regulars, with the magnitude of this effect increasing with age. The acceptability of novel irregulars was shown to increase as a function of similarity to existing irregulars, with no developmental changes observed. These findings are discussed in the light of 3 current models of past-tense acquisition: the single-route model (e.g., Bybee & Moder, 1983), the dual-route model (e.g., Prasada & Pinker, 1993), and the multiple-rules model (e.g., Albright & Hayes, 2003).

This study investigates how the duration of the stem vowel of regular and irregular English verbs is modulated by tense (present and past), regularity, lexical frequency, gang size of the vocalic alternation, imageability ratings, and vowel quality. The vocalic durations of 48 monosyllabic irregular verbs and 171 regular verbs were extracted from the Buckeye Corpus of spontaneous speech. A linear mixed effects regression model revealed that vowels of past tense forms tend to have longer durations than vowels of present tense forms, that vowels of words that are less imageable are realized with shorter durations, and that tense vowels are longer than lax vowels. Surprisingly, higher frequency irregular past tense forms were produced with longer vowels, contradicting Aylett and Turk [(2004); (2006)] and Bell et al. [(2003); (2009)]. Further, vowels were shorter for irregular verbs with larger vocalic alternation gangs, contradicting the predictions of Kuperman et al. [(2007)] but supporting hypotheses that units with a smaller information load have shorter durations. This pattern of results is interpreted as a consequence of the pressure for regularization during the production of irregular past tense forms.

There is substantial debate over the mental representation of regular past tense forms in both first language (L1) and second language (L2) processing. Specifically, the controversy revolves around the nature of morphologically complex forms such as the past tense –ed in English and how morphological structures of such forms are represented in the mental lexicon. This study focuses on the results of a speeded acceptability judgment task testing English regular past tense forms of high- and low frequencies. In this task, participants judged the acceptability of sentences as quickly and accurately as possible. Thirty-two intermediate-to-advanced L1 Persian and L1 Arabic speakers (L2ers) and twenty-two Native speakers (NSs) of English made acceptability judgments for regular past tense forms of high- and low-frequency verbs in sentential contexts. Considering participants’ reaction times (RTs) and accuracy rates as the dependent variables, the main results are as follows. Despite NSs’ faster RTs and higher accuracy scores, both groups demonstrated the same pattern of accuracy rates and RTs. Specifically, for accuracy data, regular verbs yielded a reverse frequency effect or anti-frequency effect in both groups (i.e., lower accuracy rates for high- than low-frequency regular forms in NSs as well as L2ers). For RT data, while the NSs exhibited a marginally anti-frequency effect, the L2ers displayed a nonsignificant trend for the anti-frequency effect. These results support the dual-mechanism models suggesting that the mental mechanisms and representations of inflectional morphology are the same in NSs and intermediate-to-advanced L2ers.

The present study investigated the acquisition of the irregular past tense in an online setting through a positive psychology lens. Due to the learning and contextual needs of the participant, the pedagogical efforts of this research project were put on her linguistic as well as sociocultural development. The constructs involved were foreign language enjoyment (FLE) and linguistic self-confidence (LSC), which have been studied in relation to other sociolinguistic variables inside the classroom. The current study aimed to a) analyze an EFL student’s foreign language enjoyment while speaking to other English-language users through a video chat online platform and b) analyze the role of foreign language enjoyment in relationship to the oral production of irregular past tense verbs in online conversations. To achieve these objectives, a mixed-methods design was used in the context of a case study. Data was obtained from pre- and post-intervention interviews with the student, in which her FLE and LSC levels were measured as well as her irregular past tense performance, and oral interactions with other English speakers from around the globe through the HelloTalk language-learning app. It was found that the factors of the participant’s FLE and LSC were positively influenced by the intervention and that the accurate production of irregular past-tense forms is related to a learner’s LSC levels. This piece of research sheds light on ways of boosting L2 learners’ FLE and, more specifically, their LSC by using social-media-like language-learning tools for oral practice and real-life interaction.

Difficulty with marking past tense verbs is a clinical indicator of language disorders. However, there is too little information on language development in bilingual children living in multilingual and multicultural countries like Singapore to accurately diagnose language disorders. In this study, we aimed to understand language development in Singaporean English-Mandarin bilingual children by examining narrative-level discourse. We conducted secondary analysis of a large data set collected in Singapore. Here, we report on a total of 36 English-dominant and balanced English-Mandarin bilingual participants who produced narratives in English and Mandarin elicited via retell tasks using wordless picture books. Participants had been allocated to language dominance groups based on parental reports and performance on vocabulary tasks. We explored their productions of English regular and irregular past tense verb forms and Mandarin perfective aspect markers and examined the effect of language dominance on production of target forms. There was no significant difference between the language dominance groups on any outcome measures. Participants produced significantly more irregular past tense verb forms than regular past tense markers in English. The percentage accuracy of regular and irregular past tense verb forms was positively correlated with English expressive vocabulary scores. There was no significant correlation between Mandarin perfective aspect markers and Mandarin vocabulary scores. These findings suggest that acquisition of past tense marking in bilingual children is dependent on exposure to target verb forms. By providing normative data, these results can support clinical decision making around assessment and diagnosis of language disorders in linguistically complex communities in which there are limited standardized assessment tools normed on relevant populations.

We investigated whether children's inhibitory control (IC) is associated with their ability to produce irregular past tense verb forms as well as learn from corrective feedback following overregularization errors. Forty-eight 3;6 to 4;5 year old children were tested on the irregular past tense and provided with adult corrective input via models of correct use or recasts of errors following ungrammatical responses. IC was assessed with a three-item battery of tasks that required suppressing a prepotent response in favor of a non-canonical one. Results showed that IC was associated with children's initial production of irregular forms, but not associated with their post-feedback production. Findings are discussed in terms of current theories of past tense use and acquisition.

This study investigated structural variation in tense usage between Nigerian English (ICE-Nigeria) and Standard British English (BNC) through a corpus-based comparative approach. Using data drawn from both spoken and written genres in the two corpora, the analysis combined quantitative frequency counts with qualitative examination of concordance lines to identify patterns in the present, past, and future tenses. The present tense emerged as the most frequent in both varieties, but Nigerian English demonstrated an extended functional range for the progressive aspect, including its use with stative verbs and for habitual actions. In the past tense, both varieties exhibited similar proportions of regular and irregular forms, but Nigerian English showed higher use of the past continuous and past perfect, suggesting a preference for explicit temporal sequencing. For the future tense, both corpora favoured will, though Nigerian English retained more frequent use of shall, reflecting formal register tendencies. These findings were interpreted within Kachru’s World Englishes framework, highlighting Nigerian English as a nativised variety shaped by indigenous language influence, sociocultural norms, and historical contact with British English. The study argued that these patterns were systematic rather than erroneous, underscoring the legitimacy of Nigerian English as a distinct variety. The results had implications for English language teaching in Nigeria, advocating for pedagogical approaches that recognised local usage patterns while maintaining international intelligibility. The research demonstrated the value of corpus-based methods in capturing grammatical variation and called for further comparative studies across African Englishes to deepen understanding of tense usage in World Englishes.

The overgeneralization of morphological forms as a function of experience

We examine the role of off-line memory consolidation processes in the learning and retention of a new quasi-regular linguistic system similar to the English past tense. Quasi-regular systems are characterized by a dominance of systematic, regular forms (e.g., walk-walked, jump-jumped) alongside a smaller number of high frequency irregulars (e.g., sit-sat, go-went), and are found across many cognitive domains, from spelling-sound mappings to inflectional morphology to semantic cognition. Participants were trained on the novel morphological system using an artificial language paradigm, and then tested after different delays. Based on a complementary systems account of memory, we predicted that irregular forms would show stronger off-line changes due to consolidation processes. Across two experiments, participants were tested either immediately after learning, 12 h later with or without sleep, or 24 h later. Testing involved generalization of the morphological patterns to previously unseen words (both experiments) as well as recall of the trained words (Experiment 2). In generalization, participants showed ‘default’ regularization across a range of novel forms, as well as irregularization for previously unseen items that were similar to unique high-frequency irregular trained forms. Both patterns of performance remained stable across the delays. Generalizations involving competing tendencies to regularize and irregularize were balanced between the two immediately after learning. Crucially, at both 12-h delays the tendency to irregularize in these cases was strengthened, with further strengthening after 24 h. Consolidated knowledge of both regular and irregular trained items contributed significantly to generalization performance, with evidence of strengthening of irregular forms and weakening of regular forms. We interpret these findings in the context of a complementary systems model, and discuss how maintenance, strengthening, and forgetting of the new memories across sleep and wake can play a role in acquiring quasi-regular systems.

The present study used event-related potentials to investigate whether the processing of grammatical gender agreement involving gender regular and irregular forms recruit the same or distinct neurocognitive mechanisms and whether different grammatical gender agreement conditions elicit the same or diverse ERP signals. Native speakers of Brazilian Portuguese read sentences containing congruent and incongruent grammatical gender agreement between a determiner and a regular or an irregular form (condition1) and between a regular or an irregular form and an adjective (condition2). However, in condition 2, trials with incongruent regular forms elicited more positive ongoing waveforms than trial with incongruent irregular forms. We found a biphasic LAN/P600 effect for gender agreement violation involving regular and irregular forms in both conditions. Our findings suggest that gender agreement between determiner and nouns recruits the same neurocognitive mechanisms regardless of the nouns' form and that, depending on the grammatical class of the words involved in gender agreement, differences in ERP signals can emerge.