Recent controversy about the innateness of language has awakened interest in the genetic basis of linguistic development. In this study, we analysed more extensively data from Mather & Black (1984).in order to test the hypothesis that the speech articulation of monozygotic (MZ) twins would be qualitatively more similar than that of age- and sex-matched dizygotic (DZ) twins. Analyses revealed that 4–year-old MZ twin pairs were significantly more likely to misproduce the same sounds on an articulation test than were DZ twin pairs, and that DZ twins were no more likely to share errors than were children who were both genetically and environmentally unrelated. There was no evidence that MZ twins made more similar errors than DZ twins, and indeed it was difficult to make this determination since only broad categories of error (substitution, distortion, omission) were available for analysis. The greater amount of genetic material shared by MZ twins, and the presumably more similar morphology of their speech mechanisms, may have caused certain sound patterns to be of more nearly equal difficulty for both members of a MZ pair. However, these findings need to be confirmed with phonetically more detailed analyses.

This study examines the mental processes involved in children's on-line recognition of inflected word forms using event-related potentials (ERPs). Sixty children in three age groups (20 six- to seven-year-olds, 20 eight- to nine-year-olds, 20 eleven- to twelve-year-olds) and 23 adults (tested in a previous study) listened to sentences containing correct or incorrect German noun plural forms. In the two older child groups, as well as in the adult group, over-regularized plural forms elicited brain responses that are characteristic of combinatorial (grammatical) violations. We also found that ERP components associated with language processing change from child to adult with respect to their onsets and their topography. The ERP violation effects obtained for over-regularizations suggest that children (aged eight years and above) and adults employ morphological computation for processing purposes, consistent with dual-mechanism models of inflection. The observed differences between children's and adults' ERP responses are argued to result from children's smaller lexicons and from slower and less efficient processing.

Young children answer many questions every day. The extent to which they do this in an adult-like way – following Grice's Maxim of Quantity by providing the requested information, no more no less – has been studied very little. In an experiment, we found that two-, three- and four-year-old children are quite skilled at answering argument-focus questions and predicate-focus questions with intransitives in which their response requires only a single element. But predicate-focus questions for transitives – requiring both the predicate and the direct object – are difficult for children below four years of age. Even more difficult for children this young are sentence-focus questions such as “What's happening?”, which give the child no anchor in given information around which to structure their answer. In addition, in a corpus study, we found that parents ask their children predicate-focus and sentence-focus questions very infrequently, thus giving children little experience with them.

The spelling of words in English is governed in part by the morphemes that make them up. This study examines the strength of children's knowledge of the role of root morphemes in spelling, specifically focusing on whether it can withstand interference by phonological changes. A total of 75 children between seven and nine years of age were given the first parts of two-morpheme transparent and opaque derived words (e.g. musical and objection) and one-morpheme control words (e.g. metal and portion). Children used the clues to a significant extent with the two-, but not the one-morpheme words. This effect was consistent across age groups and across both types of derived words. This is evidence that children's understanding of the link between morphemes and spelling is not impeded by changes in the sound of morphemes. These findings have substantial implications for models of spelling development and for educational practice.

To examine the possible persistence of phonological selectional constraints on young children's lexical choices, the words attempted in the conversational speech of a longitudinal sample of 12 normally-developing preschoolers from age 2;0 to 5;0 were scored for syllabic length, presence of consonant clusters, and distribution of constituent phonemes. Except at the youngest ages, few developmental changes in target word characteristics were seen, and the observed differences were largely accounted for by syntactic, lexical, and pragmatic factors. The results suggest that selectional constraints persist only briefly in the course of language acquisition.

Children aged 2;6–4;0 were asked questions containing comparative and superlative forms of adjectives from pairs designated as unmarked/marked or simply positive/negative. Children's answers required a choice of one out of five objects. Differences in frequency of correct responses were generally greater between unmarked/marked pairs than between simple positive/negative pairs, but the response of ‘greatest extent’ to marked adjective questions was seldom a significantly common error. Linguistic arguments for the unmarked/marked distinction in comparative adjectives are reviewed, and it is concluded that there is no linguistic or behavioural evidence for a marking explanation of children's difficulty with ‘marked’ comparative adjectives.

This study investigated the relationship between control and coreference using an act-out task involving 81 children ranging in age from 3;1 to 8;0 and eight adults ranging in age from 30 to 55. The results replicated previous findings in revealing five developmental stages in children's interpretation of PRO, an empty pronominal element. A significant relationship was observed in the patterns of children's interpretation of forwards sentences containing PRO and those containing overt pronouns. However, there was no relationship in the development of restrictions on control and restrictions on coreference.

A set of tri-zygotic quadruplets, three girls and one boy, participated in weekly observations from 1;2 to 1;10 (years;months), a period of transition from prelinguistic gesture to 50 words. In the study, one girl served as a genetic mate to her identical twin and a biological risk mate to her fraternal sister. The biological risk mates achieved milestones in lexical development at similar times; however, the genetic mates demonstrated more similarities in pattern of lexical development and in the modality of their word productions. Degree of similarity changed over the observation period. Imposed upon the natural experiment was a within-subject manipulation of the social environment: The experimenters modelled a core vocabulary via the gesture+verbal modalities to the children during each visit. The modelling resulted in increased rates of word learning for three of the children; the child with the greatest biological risk, the boy, derived the greatest benefit. The findings provide unique support for a dynamic, multi-factorial model of lexical development involving the interaction of genetics, the biological environment and the social environment. Furthermore, they illustrate the robustness of early lexical development in the face of biological risks.

Most evidence concerning cross-linguistic variation in noun bias, the preponderance of nouns in early expressive lexicons (Gentner, 1982), has come from comparisons of monolingual children acquiring different languages. Such designs are susceptible to a number of potential confounders, including group differences in developmental level and sociodemographic characteristics. The aim of this study was to quantify noun bias in bilingual Mandarin–English toddlers whose expressive lexicons in each language contained 50–300 words. Parents of fifty children (1;10–2;6) reported separately on their English and Mandarin expressive lexicons. The mean percentage of Mandarin nouns (38%) was significantly lower than the percentage of English nouns (54%) and was robust to analyses of twelve potential covariates. Analyses of the most frequently reported words suggested that lexical reduplication could be considered as a potential influence on vocabulary composition in future studies. Results suggest that characteristics of the input significantly shape early lexicons.

In order to address gaps in the literature surrounding the acquisition of translation equivalents (TEs) in young bilinguals, two experiments were conducted. In Experiment 1, TEs were measured in the expressive vocabularies of thirty-four French–English bilinguals at 1;4, 1;10, and 2;6 using the MacArthur Bates CDI. Children's acquisition of TEs occurred gradually, with more balanced ratios of exposure and vocabulary associated with larger proportions of TEs at each wave. Experiment 2 compared a direct measure of TE comprehension with parent report of the same set of words. Results showed that parents may over-report children's TE comprehension, as our sample of two-year-old French–English bilinguals (n = 20) comprehended fewer TEs on a direct measure of receptive vocabulary than parents reported on the vocabulary checklist. The present study provides an original contribution to the literature on bilingual vocabulary development by employing both a longitudinal design and a direct measure of TE comprehension.

In this paper we report a large-scale developmental study of early productive vocabulary acquisition by 928 Chinese-speaking children aged between 1;0 and 2;6, using the Early Vocabulary Inventory for Mandarin Chinese (Hao, Shu, Xing & Li, 2008). The results show that: (i) social words, especially words for people, are the predominant type of words in Chinese-speaking children's earliest productive vocabulary; (ii) overall, Chinese-speaking children's vocabulary contains greater proportions of nouns than other word categories, especially at the earliest vocabulary stage; and (iii) verbs tend to appear earlier for Chinese-speaking children as compared with English-speaking children at the same levels of vocabulary development. In addition, our study has identified the underlying variables that influence the age of acquisition of words, specifically, the interplay between the conceptual (imageability) and linguistic properties (word frequency, word length, and grammatical category) that jointly shape the development of Mandarin-speaking children's early vocabulary.

This study uses a structural priming technique with young Spanish speakers to test whether exposure to a rare syntactic form in Spanish (fue-passive) would increase the production and comprehension of that form. In Study 1, 14 six-year-old Spanish speakers described pictures of transitive scenes. This baseline study revealed that fue-passives were virtually non-existent in children's spontaneous speech. Using the priming technique in Study 2, an additional 56 Spanish-speaking children were exposed to fue-passive or active picture descriptions; we varied whether children repeated the modeled form. With repetition, production of fue-passives increased past baseline usage. When not asked to repeat, comprehension and production of fue-passives was no different than chance. Results extend the existing literature by experimentally testing input effects on the production and comprehension of infrequently used constructions, further corroborating the relation between input frequency and language skill. Findings are consistent with the view that an implicit learning mechanism guides language learning.

The artificial language Esperanto is spoken not only as a second language, by its proponents, but also as a native language by children of some of those proponents. The present study is a preliminary description of some characteristics of the Native Esperanto (NE) of eight speakers, ranging in age from six to fourteen years. As such, it is the first of its kind – previous works on NE are either theoretical treatises or individual case studies. We find, at least for the eight subjects studied, both bilingualism and nativization effects, differentiating native from non-native Esperanto speech. Among these effects are loss or modification of the accusative case, phonological reduction, attrition of the tense/aspect system, and pronominal cliticization. The theoretical ramifications are discussed, particularly with regard to universals of language acquisition and the effects of expressive requirements of language.

When children produce regularizations like comed, not all verbs are equally likely to be regularized. Several variables (e.g. lexical frequency) have been shown to be relevant, but not all the variability between verbs is understood. It is argued here that one predictor is which vowels are present in the base form vs. the past tense form. Using a notion of recessive vs. dominant vowel (where recessive vowels are more likely to be replaced by dominant vowels than vice versa) based on adult phonological processing, it is predicted that regularizations should be likely when the base vowel is dominant and unlikely when the past tense vowel is dominant. Data from 17 children reported in the literature, aged 1;6–5;6, show that this prediction is correct. Implications for the role of phonological variables in the processing of irregular past tense forms are discussed.

This investigation focuses upon an outstanding aspect of child phonology – that of consonant harmony, relabelled ‘phonological harmony’ – and inquires whether representational or processing deficits are responsible for its occurrence. A detailed analysis of the oral output of one German-speaking girl (2;7.15–2;11) supports the contention that the Imperfect Processing Model fares much better in accounting for her harmony strategy than the Incomplete Representation Model. It is established that bilabial harmony is the only type of assimilation she has recourse to, and that this process is mainly used to cope with difficult sounds, although it also implicates consonants which do not pose a production problem. The difficult sounds are arguably not absent from the child's system because they can be uttered in some positions though not in others. The harmonizing tendency is interpreted within the interactive activation model of language production and is claimed to emanate from two particularities of her processing system. She has represented even the difficult elements as network nodes, but some connections between the segment and the feature level are ill developed. As a result, activation cannot spread smoothly between these levels and the relevant units cannot be made available for production. In addition, an excessive linkage strength has been built up among the node [bilabial] and all its associates at the segment level. This puts bilabial consonants into a state of hyperactivation and allows them even to intrude upon those segments which have been perfectly mastered. It is finally shown why these two mechanisms are very unlikely to become permanent features of the child's processing system.

This study explored preschool age and gender differences in help-seeking within the theoretical framework of scaffolded problem-solving and self-regulation (Bruner, 1986; Rogoff, 1990; Vygotsky, 1978; 1986). Within-subject analyses tracked changes in help-seeking among 62 preschoolers (34 boys, 28 girls, mean age 4.22 years) solving a challenging puzzle with an adult. The goal was to document whether age and gender interact with fluctuating difficulty to affect children's spontaneous help-seeking. ANOVAs indicated that girls used more help-seeking during difficult segments of the task, despite performance equal to the boys. This pattern was strongest among older girls, who outperformed all other children and used the most help-seeking. Partial correlations, controlling for solving time, indicated that age predicted children's help-seeking during the most difficult segments of the task, but only among girls. Gender differences in social–linguistic maturation and cognitive development are discussed within the framework of Vygotskian theory and related educational practice.

Children (mean age 3; 6) were tested as to the comprehension of the deictic words this, that, here and there in two conditions: as hearers–addressees and as hearers–spectators. It was hypothesized that comprehension of these words depends on the role the comprehender plays in the conversation, and that a spectator's role is more difficult than an addressee's. Comprehension in a pragmatic condition (with a pointing gesture accompanying the utterance) was contrasted with a semantic condition (without gesture), and the prediction was that the pragmatic use of the words would facilitate comprehension. It was also theorized that this and here are marked, whereas that and there are unmarked. Therefore, it was predicted that this and here would be more difficult to comprehend than that and there. All the initial predictions were confirmed by the analysis of variance. The results are discussed within recent theories of pragmatics, semantics and cognitive development.

This study examines the relationship between maternal-report measures of referential vocabulary and observational measures of referential vocabulary and usage in eight first-born middle-class children at 50 and loo words. The results indicate that although maternal-report measures of vocabulary composition can be reasonably reliable, provided some attempt is made to restrict variation in the number of vocabulary items upon which they are based, such measures tend to exaggerate the relative importance of common nouns for the child in two ways; firstly, in the sense that they reflect differential maternal sensitivity to such word-types in comparison with other less-‘referential’ items; and, secondly, in the sense that they overestimate the extent to which such word-types actually occur in the child's spontaneous speech.

This study examined the effect of lexical aspect on children's imitation accuracy of English tense-aspect morphology. Thirty-five typically developing children, ages 2;4 to 3;1, imitated sentence-pairs in which the same regular verb was used once in an activity (skip on the rug) and once in an accomplishment (skip out the door). Children imitated past-imperfective morphology equally well in accomplishments and activities, but they imitated past-perfective morphology with higher accuracy in accomplishments than activities. These findings suggest that children's early morphology development is influenced by lexical aspect conveyed at the sentence level, as predicted by the PROTOTYPE HYPOTHESIS.