The production of third-person /s/ on English verbs seems to be ahead of comprehension. Mainstream American English (MAE) is contrasted with African American English (AAE), in which /s/ is rarely supplied. Two studies explored what information children get solely from /s/ on the end of a verb. Sixty-five MAE- and 65 AAE-speaking four- to seven-year-olds participated in one of two experimental picture-choice comprehension studies. Neither group of four-year-olds could use the /s/ to determine if the event was generic rather than past tense on a verb (e.g. cuts/cut), or whether it was a verb or a noun compound as in The penguin dresses/The penguin dress. MAE-speakers do not use the information in third-person /s/ alone until age five, and not reliably until age six years. In keeping with AAE production, AAE-speaking children do not use the information in /s/ at all in this age range.

The purpose of this study was to determine the natural order of acquisition of the proform it, comparing deictic pronoun it, anaphoric pronoun it and expletive it. Files from four children (Adam, Eve, Nina and Peter) aged 1 ; 6–3 ; 0 in the CHILDES database were coded for occurrences of NP it (here it is) and expletive it (it's raining). Occurrences of NP it were coded for whether they followed an overt discourse anaphor (anaphoric it) or not (deictic it). All children examined produce deictic and anaphoric pronoun it from the very first files, but do not produce expletive it until 2–7 months later. Following Inoue's (1991) lexical-semantic reanalysis account of the acquisition of expletive there after locative there, we propose that children acquire expletive it by reanalyzing referential pronoun it to include an expletive subtype. This reanalysis takes place when children realize that expletive it never co-occurs with any deictic/anaphoric referent.

The study evaluated whether durational and allophonic cues to word boundaries are intrinsic to syllable production, and so acquired with syllable structure, or whether they are suprasyllabic, and so acquired in phrasal contexts. Twenty preschool children (aged 3 ; 6 and 4 ; 6) produced: (1) single words with simple and complex onsets (e.g. nail vs. snail); and (2) two-word phrases with intervocalic consonant sequences and varying boundary locations (e.g. this nail vs. bitty snail). Comparisons between child and adult control productions showed that the durational juncture cue was emergent in the four-year-olds' productions of two-word phrases, but absent elsewhere. In contrast, the allophonic cue was evident even in the three-year-olds' productions of single words. Perceptual judgments showed that age- and type-dependent acoustic differences translated into differences in listener behavior. The differential acquisition of the two juncture cues is discussed with reference to the acquisition of articulatory timing control.

We report four act-out experiments testing the sensitivity of adults and three- to five-year-old children to the distinction between restrictive and non-restrictive relative clauses in English. Specifically, we test knowledge of the fact that restrictive relative clauses cannot modify a proper name head, and of the fact that relatives introduced by that (as opposed to a wh-pronoun) are obligatorily restrictive. Both children and adults show knowledge of these properties. No support was found for the hypothesis that children extend the block on proper name heads to wh-relatives. Both children and adults are sensitive to the syntactic context (double object vs. existential) in which the relative clause is embedded. However, adults differ from children in four respects. First, in the double object context, adults are more likely than children to commit the error of construing a that relative as referring to a proper name head. Second, the effect of syntactic context on selection of a head is larger for adults than for children. Third, for adults, but not for children, the effect of syntactic context interacts with the type of relative clause. Fourth, adults, but not children, are influenced by whether they hear the existential context before the double object context. We propose that by three to four years of age children have acquired an adult-like grammar of relative clauses, and that the differences we see in child and adult performance can be attributed to that grammar in combination with a mature (adult) or immature (child) sentence processing capacity.

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.

Using the weird word order methodology (Akhtar, 1999), we investigated children's understanding of SVO word order in French, a language with less consistent argument ordering patterns than English. One hundred and twelve French children (ages 2;10 and 3;9) heard either high or low frequency verbs modelled in either SOV or VSO order (both ungrammatical). Results showed that: (1) children were more likely to adopt a weird word order if they heard lower frequency verbs, suggesting gradual learning; (2) children in the high frequency conditions tended to correct the ungrammatical model they heard to the closest grammatical alternative, suggesting different models activated different grammatical schemas; and (3) children were less likely to express the object of a transitive verb than were English children in an equivalent study, suggesting object expression is more difficult to master in French, perhaps because of its inconsistency in the input. These findings are discussed in the context of a usage-based model of language acquisition.

Parents' object labels can be distinguished by whether the child is already attending to the object (follow-in) or not (lead-in). Lead-in labels have been found to be associated with low vocabulary. The current study examines whether the relation between lead-in labels and child vocabulary is influenced by whether the child's attention is redirected. Eighteen mother–infant dyads were videotaped at 1 ; 2, 1 ; 6 and 1 ; 10. Results indicate that parents' use of successful lead-in labels is positively correlated with children's vocabulary, whereas use of unsuccessful labels is negatively correlated. Finally, use of gesture is associated with the redirective success of lead-in labels.

This study examined two- (n=10) and three-year-old (n=16) French–English bilingual children’s repairs of breakdowns in communication that occurred when they did not use the same language as their interlocutor (Language breakdowns) and for other reasons (e.g. inaudible utterance). The children played with an experimenter who used only one language (English or French) during the play session. Each time a child used the other language, the experimenter made up to five requests for clarification, from non-specific (What?) to specific (Can you say that in French/English?). The experimenter also made requests for clarification when breakdowns occurred for other reasons, e.g. the child spoke too softly, produced an ambiguous utterance, etc. Both the two- and three-year-olds were capable of repairing Language breakdowns by switching languages to match that of their experimenter and they avoided this repair strategy when attempting to repair Other breakdowns. Moreover, they switched languages in response to non-specific requests. The results indicate that even two-and-a-half-year-old bilingual children are capable of identifying their language choice as a cause of communication breakdowns and that they can differentiate Language from Other kinds of communication breakdowns.

Previous research has examined children's ability to add inflections to nonsense words. The current experiments were designed to determine whether children, ranging in age from 1 ; 9 to 2 ; 10 (N=34), could demonstrate productivity by dropping verbal inflections. In Experiment 1, children added -ed and -ing to novel stems, and dropped them from novel inflected forms and did so largely appropriately. In Experiment 2, they dropped -ing from verbs, but not from nouns, suggesting that when young children drop inflections they tend to do so appropriately, and not simply for ease of pronunciation.

This study examined 32 children’s (M age=1;8 years) engagement in joint attention (JA) and the relation between JA and vocabulary size across mother–child (MC) and mother–child–sibling (MCS) contexts. In the MCS context, mothers engaged in JA more with one child than both children; they engaged in less JA with target child than they did in the MC context. JA style was generally unrelated across the contexts. Coordinated JA and children’s vocabulary were significantly related only for the MCS context. Findings suggest the number of social partners influences JA dynamics and multi-child contexts can be positive language learning environments.

Characterizing early communicative development in children with Autism Spectrum Disorders (ASD) is valuable for understanding profiles of ability in this population. The current investigation was modeled on Charman, Drew, Baird & Baird (2003b). Analyses explored parent report of early vocabulary, non-verbal communication, functional object use and play skills on the MacArthur-Bates Communicative Development Inventory (CDI) in 93 children with ASD, 31 children with developmental delay (DD) and 29 typically developing children. Results were generally consistent with those of Charman and colleagues (2003b), suggesting that skills improve with increasing non-verbal mental age and chronological age but that most children with ASD are delayed in receptive and expressive vocabulary and non-verbal communication, functional object use and play skills. Vocabulary profiles in the ASD sample were similar to those in the comparison samples, as was the developmental pattern of gesture and vocabulary mastery. However, when compared to published norms, children with ASD may show less of a discrepancy between their receptive and expressive vocabulary.

The ability to extract meaning through the use of syntactic cues, adapted from Naigles' (1990) paradigm, was investigated in Hebrew-speaking children with autism, those with specific language impairment (SLI) and those with typical language development (TLD), in an attempt to shed light on similarities and differences between the two diagnostic categories, both defined by primary language deficits. Thirteen children with autism and 13 with SLI were matched on chronological age, level of language functioning and gender, and 13 children with TLD were matched to the children in the two clinical groups according to language level, as measured by the CELF-P. Children with autism and children with TLD learned novel words using the syntactical cues in the sentences in which they were presented, whereas children with SLI experienced more difficulty, learning only that which would be expected from chance according to the binomial test. Only 4 of the 13 children with SLI (31%) learned the new words, whereas 11 children with autism and 10 children with TLD learned the novel verb using syntactical cues from the sentence frame. The results are analyzed in terms of possible underlying mechanisms in language acquisition. Children with autism seem to rely on relatively intact syntactic abilities, while children with SLI seem to have marked impairment in using this mechanism in acquiring word meaning. Implications for future research and intervention with preschool children with primary language disorders are discussed.

When presented with a pair of objects, one familiar and one unfamiliar, and asked to select the referent of a novel word, children reliably demonstrate the disambiguation effect and select the unfamiliar object. The current study investigated two competing word learning accounts of this effect: a pragmatic account and a word learning principles account. Two-, three- and four-year-olds were presented with four disambiguation conditions, a word/word, a word/fact, a fact/word and a fact/fact condition. A pragmatic account predicted disambiguation in all four conditions while a word learning principles account predicted disambiguation in the word/word and fact/word conditions. Results indicated that children disambiguated in word/word and fact/word conditions and two-year-olds disambiguated at above chance levels in the word/word condition but at below chance levels in the fact/fact condition. Because disambiguation varied both as a function of age and condition these findings are presented as challenges to a pragmatic account of the disambiguation effect.

It is claimed by Totereau, Thévenin & Fayol (1997) that French children understand the rule for spelling the plural inflection very early on. However, no evidence contradicts the alternative that they learn the spelling of a word's singular and plural forms by treating the two forms as entirely different words. We tested this by asking French first and second graders (85 six-year-old and 89 seven-year-old children, respectively) to read and write rare words, either in just the singular or in just the plural, and then testing their spelling. The children tended to attach plural inflections to words which they had encountered only as plural and to omit them from words encountered before only as singular.

This study examined the effects of being born very preterm on children's early language development using prospective longitudinal data from a representative regional cohort of 90 children born very preterm (gestational age <33 weeks and/or birth weight <1,500 grams) and a comparison sample of 102 children born full term (gestational age 38–41 weeks). The MacArthur-Bates Communicative Development Inventory: Words and Sentences (CDI-WS) was used to assess children's language development at age 2 ; 0 (corrected for gestational age at birth). Clear linear relationships were found between gestational age at birth and later language outcomes, with decreasing gestational age being associated with poorer parent-reported language skills. Specifically, children born extremely preterm (<28 weeks' gestation) tended to perform less well than those born very preterm (28–32 weeks' gestation), who in turn performed worse than children born full term (38–41 weeks' gestation). This pattern of findings was evident across a range of outcomes spanning vocabulary size and quality of word use, as well as morphological and syntactic complexity. Importantly, associations between gestational age at birth and language outcomes persisted after statistical control for child and family factors correlated with both preterm birth and language development. These findings demonstrate the presence of pervasive delays in the early language development of children born very preterm. They also highlight the importance of gestational age in predicting later language risk in this population of infants.

German children aged 2 ; 1 heard a sentence containing a nonce noun and a nonce verb (Der Feks miekt). Either the noun or the verb was prosodically highlighted by increased pitch, duration and loudness. Independently, either the object or the action in the ongoing referential scene was the new element in the situation. Children learned the nonce noun only when it was both highlighted prosodically and the object in the scene was referentially new. They did not learn the nonce verb in any condition. These results suggest that from early in linguistic development, young children understand that prosodic salience in a sentence indicates referential newness.

The vocabulary development of 24 Italian children aged between 1 ; 4 and 1 ; 6 at the beginning of the study was longitudinally monitored on a monthly basis using the Italian version of the MacArthur Communicative Development Inventory drawn up by their mothers. This study analyzes data from children for whom two sampling stages were available; the first corresponding to a vocabulary size as close as possible to 200 words (mean 217, range 167–281), the second to a vocabulary size ranging from 400 to 650 words (mean 518, range 416–648). The children's vocabulary composition was analyzed by calculating, for each sampling stage, the percentage of common nouns, verbs and closed-class words. The increase in percentage points of the various lexical items between the first and second sampling stages was also analyzed. Data confirmed the predominance of nouns over verbs and closed-class words at both sampling stages, while verbs and closed-class words showed a higher percentage increase than nouns. The results provide evidence that children who reached the first sampling point at an earlier age had a higher percentage of nouns than children who reached the same stage at an older age. However, in the passage from the first to the second sampling point no relationship emerged between a style of acquisition based on the acquisition of nouns and an increase in the rate of vocabulary growth.