This paper investigates developmental changes, as well as inter-linguistic and inter-individual variations, in the expansion and composition of French children's early lexicons. Two studies were conducted using children's naturalistic productions: a longitudinal study of one child between 1;2 and 2;6, and a cross-sectional study of two groups (12 children each) aged 1;8 and 2;6. Analyses indicate that lexical productivity (measured in types, tokens, and new words) strongly increased with age, whereas lexical diversity showed almost no developmental progression. Nouns and para-lexical elements (including interjections, fillers or formulas) were predominant until 1;8 and decreased over time, while predicates and grammatical words increased. As compared to English, French development was characterized by less frequent nouns, initially more frequent predicates, and a remarkable expansion of grammatical words. Inter-individual variability in lexical productivity, in lexical diversity, and in the proportions of different categories was more marked at 1;8 than at 2;6. Lexical profiles found at 1;8 suggest the existence of more diversified organizational patterns than those captured in the referential-expressive distinction.

The present study tested the hypothesis that children as young as two use what adults tell them about meaning relations when they make inferences about new words. 18 two-year-olds (mean age 2;2) and 18 three-year-olds (mean age 3;2) learned two new terms (a) with instructions either (i) to treat one term as a superordinate to the other, or (ii) to replace one term with another; and (b) with no instruction given about how two new words might be related. Children were attentive to both kinds of instructions or pragmatic directions, and made use of them in their word-learning. When they received no instruction relating the two new words, they resorted to a range of coping strategies to assign and relate meanings to each other. These findings support the view that children's learning of new word meanings is guided by the pragmatic directions adults offer.

This issue contains a new Review Article and Discussion section. The idea is to ask a leading researcher to contribute an article which can either be a review of a field or an extended book review and to then ask for commentaries on the piece by other researchers. In this issue the section consists of a commentary by Michael Tomasello on Adele Goldberg's Constructions: a construction grammar approach to argument structure together with twelve commentaries and a reply. The next of these sections will be an extended review by Matthew Rispoli of Rethinking innateness: a connectionist perspective on development by Jeffrey Elman, Elizabeth Bates, Mark Johnson, Annette Karmiloff-Smith, Domenico Parisis and Kim Plunkett. I very much hope that readers will find the new section an interesting and useful contribution to theoretical and methodological discussion in the field. Of course the success of this venture depends on contributions from a wide range of theoretical perspectives and on people's willingness to make these contributions even where they sharply disagree with the thesis of the review article.

Derived nominals are abstract nouns derived from verbs and adjectives by nominalization. This study traces the route taken by Hebrew-speaking children in the acquisition of Hebrew derived nominals (HDNs) of two types: action nominals which conform in structure to the small set of obligatory verb patterns (binyanim) (e.g. ktiva ‘writing’) and deverbal nouns, which belong to separate nominal patterns (e.g. maga ‘touch’). One hundred native speakers of Hebrew (children aged 5, 8, 11 and 15, and adults) were tested on comprehension and production of HDNs. The test items were grouped by binyan patterns and by morphological regularity. Results showed that acquisition of HDNs starts at about age 8 and is not complete by age 15, and that task type, binyan pattern and morphological regularity all affect ease of acquisition. We consider the strategies employed in the course of acquisition of HDNs and offer an explanation for this late acquisition which requires a vast amount of prior integrated knowledge.

Generic noun phrases (e.g. Tigers are fierce) are of interest for their semantic properties: they capture ‘essential’ properties, are timeless, and are context-free. The present study examines use of generic noun phrases by preschool children and their mothers. Mother–child pairs were videotaped while looking through a book of animal pictures. Each page depicted either a single instance of a particular category (e.g. one crab) or multiple instances of a particular category (e.g. many crabs). The results indicated a striking difference in how generics vs. non-generics were distributed, both in the speech of mothers and in the speech of preschool children. Whereas the form of non-generic noun phrases was closely linked to the structure of the page (i.e. singular noun phrases were used more often when a single instance was presented; plural noun phrases were used more often when multiple instances were presented), the form of generic noun phrases was independent of the information depicted (e.g. plural noun phrases were as frequent when only one instance was presented as when multiple instances were presented). We interpret the data as providing evidence that generic noun phrases differ in their semantics and conceptual organization from non-generic noun phrases, both in the input to young children and in children's own speech. Thus, this simple linguistic device may provide input to, and a reflection of, children's early developing notion of ‘kinds’.

This paper addresses the question of whether the rate and patterns of pronoun case error are influenced by the composition of an individual pronoun's paradigm. Twenty-nine children, aged 2;6 to 4;0 were audiotaped for two 1-hour sessions, interacting with their primary caregivers engaged in free play, book reading and family album viewing. It was found that her was overextended for she at a significantly higher rate than him for he and them for they, providing evidence of a ‘double-cell’ effect that increases the incidence of error in the feminine pronoun. It was also found that the overextension of nominative forms (e.g. he for him), were antagonistic to the more frequently occurring type of overextension, objective for nominative (e.g. him for he). These findings indicate that the composition of a pronoun's paradigm influenced the patterns of pronoun case error observed.

This study focuses on the acquisition of subject–verb agreement in Brazilian Portuguese. A quantitative analysis of the data produced by a Brazilian child between the ages of 3;02.07 and 3;04.08 is presented. The overall error rate is low. However, a further and more detailed analysis reveals important contrasts both in the frequency of production of different verb inflections (as regards the person/number variables within the verb morphological system) and in the rate of subject–verb agreement errors associated with them. Our findings not only suggest that subject–verb agreement may be acquired piecemeal, but also that the learning of particular verb inflections may itself be a gradual process. Alternatives to the idea of rule-governed production – such as the child's reproducing frozen subject–verb strings previously produced by adults and blending different frozen strings into novel combinations – are discussed as processes which can shed some light on the pattern of both erroneous and correct production shown by this child.

Children's overextensions (e.g. referring to a pomegranate as apple) raise intriguing questions regarding early word meanings. Specifically, how do object shape, taxonomic relatedness, and prior lexical knowledge influence children's overextensions? The present study sheds new light on this issue by presenting items that disentangle the three factors of shape, taxonomic category, and prior lexical knowledge, and by using a novel comprehension task (the screened-alternative task) in which children can indicate negative exemplars (e.g. which items are notapples). 49 subjects in three age groups participated (Ms=2;0, 2;6, and 4;5). Findings indicate: (1) Error patterns differed by task. In production, errors were overwhelmingly due to selecting items that matched the target word in both shape and taxonomic relatedness. In comprehension, more errors were based on either shape alone or taxonomic relatedness alone, and the nature and frequency of the overextensions interacted with prior lexical knowledge. (2) Error patterns also differed markedly based on the word being tested (apple vs. dog), in both comprehension and production. (3) As predicted, errors were more frequent in production than comprehension, though only for children in the two younger age groups. Altogether, the study indicates that overextensions are not simply production errors, and that both taxonomic relatedness and object shape play a powerful role in early naming errors.

The simultaneous acquisition of two languages in early childhood presents an interesting test case for language acquisition theories. Children in bilingual environments receive input which could potentially lead to output systems different to those of monolingual children. The speech of three bilingual German-English children was recorded monthly between the ages of 2;0 and 5;0. The analysis of word order in the verb phrase shows that initial structural separation was followed by an extended period of non-target structures in German before the children eventually worked out which structures overlap and which structures differentiate the two languages. The bilingual data point towards language being acquired incrementally, on the basis of cue strength and cue cost. It is suggested that the partially overlapping structures in the input from German and English create structural saliencies for the child before they are functionally accessible. Functional identification eventually leads to structural separation.

Several theoretical and descriptive challenges are presented by children's phonological substitution errors which interact to yield the effect of a chain shift. Drawing on an archival study of the sound systems of five children (ages 3;5 to 4;0) with normal development and 47 children (ages 3;4 to 6;8) with phonological delay, one such chain shift, namely the replacement of target /Θ/ by [f] and the replacement of /s/ by [Θ/, was identified in the speech of six children from the two subgroups. Different derivational and constraint-based accounts of the chain shift were formulated and evaluated against the facts of change and the children's presumed perceptual abilities. An adequate account in either framework was found to require the postulation of underspecified and, in some instances, nonadult-like underlying representations. Such representations were able to reconcile within a single-lexicon model the presumed production/perception dilemma commonly associated with acquisition. Continuity was also preserved by limiting underlying change to just those lexical items which exhibited a change phonetically.

Although children acquire Spanish subjunctive morphology early in the process of language acquisition, they only master mood selection in a staged process that lasts for several years. This paper examines the possibility that the acquisition of subjunctive mood selection in particular syntactic contexts is constrained by cognitive development in the area of representational theory of mind. Acquisition of the epistemic aspects of the semantics of subjunctive are shown to be associated with the understanding of false beliefs, a landmark development in children's cognition. Twenty-two Spanish speaking children between the ages of 3;5 and 6;11 participated in an elicited production study designed to test whether children's ability to produce subjunctive relative clauses was related to their ability to pass a false belief task. Results indicate a strong correlation between children's ability to use the subjunctive mood in relative clauses and their capacity for understanding false beliefs.

This article contributes to a debate in the linguistic and psychological literature that centres around the representation of morphologically complex words in the grammar and in the lexicon. The issue is whether inflectional morphology is rule-based (i.e. symbolically represented), or whether the assumption of pattern association is more adequate to account for the facts. On the basis of the analysis of acquisitional data the article strongly argues for the latter alternative. In a classic experiment that helped shape the development of acquisition theory Berko (1958) reported substantial support for item-and-process rules in the acquisition of plural morphology in English. A large part of her results were zero responses (repetition of the stimulus). A reinterpretation of these zero responses in light of schema theory and the cue strength hypothesis shows a striking departure from randomness. Berko's subjects tended to repeat stimuli just to the extent that these already resembled a plural schema. A reinterpretation of data reported in Innes (1974) achieved compatible results. This data set is far more extensive than Berko's and is used in the present study to put the schema model to a more stringent test. A reinterpretation of a parallel experiment with German children, using the cue strength analysis of the more complex plural morphology of German yielded parallel results. Finally, natural acquisitional data obtained from seven German speaking children aged between 2;1 and 2;9 are analysed. Again, strong support is found for the schema model. It is suggested that a schema-learning mechanism may underlie the acquisition of morphology, even when the end product of the learning process involves item-and-process rules, as in the case of English plural formation. In a schema-learning model, the child builds schematic representations for possible singular and plural lexical items as whole gestalts, and attempts to map concrete forms onto these schemata in deciding whether the forms have singular or plural value.

This study extends prior investigations of children's abilities to conceptualize distinctive phonological features in development. The purpose was to establish the relationship between a child's productive and conceptual knowledge, and to examine its potential influence on phonological change. Six children evidencing phonological disorders (aged 3;4 to 5;7) participated in evaluations of the productive sound system and the metalinguistic ability to classify phonological information, with particular emphasis on fricatives. Then, children were enrolled in clinical treatment aimed at accurate production of fricatives. Following treatment, production and classification abilities were again tested. Results indicated that if a child's productive knowledge of distinctive featural contrasts changed following treatment, there was also a corresponding change in conceptual knowledge. The specific featural dimensions that were used to classify phonological information were either in parallel to, or in advance of, those features also used in production by the child. Conceptual knowledge was thus equal to or better than productive knowledge for these children.

Twenty-four children between 2;5 and 3;1 were taught two nonce verbs. Each verb was used multiple times by an adult experimenter to refer to a highly transitive action involving a mostly animate agent (including the child herself) and a patient of varying animacy. One of the verbs was modelled in the Two-Participants condition in which the experimenter said: ‘Look. Big Bird is dopping the boat’. The other verb was modelled in the No-Participant condition in which the experimenter named the Two-Participants but did not use them as arguments of the novel verb: ‘Look what Big Bird is doing to the boat. It's called keefing’. It was found that whereas many children produced transitive sentences with the Two-Participants verb, only children close to 3;0 produced transitive sentences with the No-Participant verb. This age is somewhat younger than previous studies in which young children were asked to produce transitive sentences with two lexical nouns for the two animate participants. Also, re-analyses of previously published studies in which children learned novel verbs in sentence frames without arguments found that the few transitive sentences produced by children under 2;6 involved either I or me as subject. One hypothesis is thus that as young children in the third year of life begin to construct a more abstract and verb-general transitive construction, this construction initially contains only certain types of participants expressed in only certain kinds of linguistic forms.

This study investigated the extent to which the nature of verb input accounts for the order in which children acquire verbs. We assessed the nature of verb input using a combined sample of the speech of 57 mothers addressing their Stage I children. We assessed the order of verb acquisition using as our database a combined sample of those children's speech 10 weeks later and using as our measure of order of acquisition the frequency of verb occurrence. The first set of analyses established the validity of this measure of acquisition order by comparing it with order of acquisition data obtained from checklist and diary data. The second set of analyses revealed that three properties of the input were significant predictors of the order of acquisition of the 25 verbs that were the focus of this study. The predictive properties of input were the total frequency, final position frequency, and diversity of syntactic environments in which the verbs appeared. These findings suggest that the way verbs appear in input influences their ease of acquisition. More specifically, the effect of syntactic diversity in input provides support for the syntactic bootstrapping account of how children use structural information to learn the meaning of new verbs.

This study investigates the use of relative clauses in French children's narrative monologues. Narrative texts were collected from French-speaking monolinguals in four age groups (five, seven, ten years and adults). Twenty subjects from each group were asked to tell a story based on a picture book consisting of twenty-four images without text (Frog, Where are you?). Relative constructions were coded following the categories defined by Dasinger & Toupin (1994) into two main functional classes: general discourse and narrative functions. The results show that the use of relative clauses in general discourse functions precedes their use in more specific narrative functions. An analysis of textual connectivity (Berman & Slobin, 1994) in one episode reveals that children and adults differ in their choice of preferred structures. The results also show that children use fewer transitive predicates in relative clauses than do adults. Transitive verbs are essential for advancing the narrative plot (Hopper & Thompson, 1980). While subject relative clauses are acquired early and used frequently, the development of their multifunctional use in diverse narrative functions extends well beyond childhood.

The effect of regional accent on children's processing of speech is a theoretically and practically important aspect of phonological development that has been little researched. 48 children from London, aged four and seven years old, were tested on their ability to repeat and define single words presented in their own accent and in a Glaswegian accent. Results showed that word comprehension was significantly reduced in the Glaswegian condition and that four-year-olds performed less successfully than seven-year-olds. Both groups made similar numbers of lexical misidentifications, but the younger children were more likely to fail to access any word at all. On the repetition task, the younger children showed a different pattern of errors to the older children, their productions being apparently more influenced by the phonetics of the Glaswegian stimuli. It is suggested that such phonetic responses are related to the younger children's failure to map the unfamiliar accent onto their own phonological representations. It is proposed that the lexical misidentifications, common to both age groups, are more likely to be induced by lack of context. The paper concludes with discussion of implications of these findings for our understanding of how children develop the ability to process unfamiliar regional accents.

An empirical puzzle regarding toddlers' fast mapping motivated the current investigation. Whereas children between 1;10 and 2;1 have shown only a modest rate of mapping novel nouns onto unfamiliar rather than familiar objects, a very high rate has been observed in those between 1;4 and 1;8 (Mervis & Bertrand, 1994). Study 1 examined whether young two-year-olds (N=40, mean age=2;1) might map at a higher rate when tested with procedures unique to Mervis & Bertrand's assessment – strong corrective feedback rather than mild positive non-contingent feedback; large sets of test objects rather than pairs; presentation of easier tests first. Only the first variable affected performance in a manner that could solve the puzzle. Unfamiliar kinds were selected at a much higher rate under corrective (0·86) than non-contingent (0·57) feedback. Although nearly every child in the non-contingent group chose correctly on the first trial, many failed to do so thereafter. In Study 2, rather than presenting a test word to the children (N=16, mean age=2;2), the experimenter merely asked for ‘the one I want’. Unfamiliar kinds were selected much less often than in Study 1, suggesting that at least one lexical principle proposed in the literature underlies the noun mapping preference. Changes over trials in the two studies indicated that the noun mapping preference is quite prevalent, but unless initial choices are strongly reinforced, an increase in the salience of familiar kinds after the first trial lures some children into error. Consistent with this analysis, toddlers in Study 3 (N=24, mean age=2;1) who received non-contingent strong acceptance for their noun mapping decisions, selected unfamiliar kinds more often than those who had received non-contingent mild acceptance in Study 1.

The two studies presented here explore the relationship between children's pragmatic skills and their growth in grammar. In study 1, thirty normally developing children were videotaped interacting with their parents at 1;2 and again at 2;7. Using correlational and regression techniques, we found that pragmatic accomplishments of MUTUAL ATTENTION, as well as mother's conversational style, explained 45% of the variance in grammar at 2;7. The second study investigated pragmatic–grammatical relationships with data from 6 high-functioning children with autism. To control for individual variation in skill level at the start of the study, within-individual growth rates for grammar were estimated as our outcome. The results substantiated those of study 1, in that pragmatic accomplishments within mutual attention predicted the per month growth rate in grammar. We interpret these findings as consistent with the position that the infant's social-pragmatic skills contribute to the acquisition of grammar.

This study examines sources of individual variation in child vocabulary competence in the context of a multivariate developmental ecological model. Maternal sociodemographic characteristics, personological characteristics, and vocabulary, as well as child gender, social competence, and vocabulary competence were evaluated simultaneously in 126 children aged 1;8 and their mothers. Measures of child vocabulary competence included two measures each of spontaneous speech, experimenter assessments, and maternal reports. Maternal measures, from proximal to distal, included vocabulary, verbal intelligence, personality, attitudes toward parenting, knowledge of parenting, and SES. Structural equation modelling supported several direct unique predictive relations: child gender (girls higher) and social competence as well as maternal attitudes toward parenting predicted child vocabulary competence, and mothers' vocabulary predicted child vocabulary comprehension and two measures of mother-reported child vocabulary expression. In addition, children's vocabulary competence was influenced indirectly by mothers' vocabulary, social personality, and knowledge of child development. Maternal vocabulary itself was positively influenced by SES, maternal verbal intelligence, and mothers' knowledge about parenting. Individual variation in child vocabulary competence might best be understood as arising within a nexus of contextual factors both proximal and distal to the child.