This article addresses the effect of communicative activity on the use of language and gesture by school-age children. The present study examined oral narratives and explanations produced by children aged six and ten years on the basis of several linguistic and gestural measures. Results showed that age affects both gestural and linguistic behaviour, supporting previous findings that multimodal discourse continues to develop during the school-age years. The task (narration vs. explanation) also had clear effects on the use of language and gesture: gestures and subordinate markers were more frequent in explanations than in narratives, whereas cohesion markers were more often used in narratives. Altogether, these results show partly distinctive developmental patterns between narrative monologic discourse behaviour and explanatory behaviour in the context of dialogue and question–answer exchanges.

Although it has been often hypothesized that children learn to produce new sound patterns first in frequently heard words, the available evidence in support of this claim is inconclusive. To re-examine this question, we conducted a survival analysis of word-initial consonant clusters produced by three children in the Providence Corpus (0 ; 11–4 ; 0). The analysis took account of several lexical factors in addition to lexical input frequency, including the age of first production, production frequency, neighborhood density and number of phonemes. The results showed that lexical input frequency was a significant predictor of the age at which the accuracy level of cluster production in each word first reached 80%. The magnitude of the frequency effect differed across cluster types. Our findings indicate that some of the between-word variance found in the development of sound production can indeed be attributed to the frequency of words in the child's ambient language.

This article presents the methodology used in a population-based study of early communicative development in Norwegian children using an adaptation of the MacArthur-Bates communicative development inventories (CDI), comprising approximately 6500 children aged between 0 ; 8 and 3 ; 0. To our knowledge, this is the first CDI study collecting data via the Internet. After a short description of the procedures used in adapting the CDI to Norwegian and the selection of participants, we discuss the advantages and potential pitfalls of using web-based forms as a method of data collection. We found that use of web-based forms was far less time-consuming, and therefore also far less expensive than the traditional paper-based forms. The risk of coding errors was virtually eliminated with this method. We conclude that in a society with high access to the Internet, this is a method well worth pursuing.

Does child-directed language differ from adult-directed language in ways that might facilitate word learning? Associative structure (the probability that a word appears with its free associates), contextual diversity, word repetitions and frequency were compared longitudinally across six language corpora, with four corpora of language directed at children aged 1 ; 0 to 5 ; 0, and two adult-directed corpora representing spoken and written language. Statistics were adjusted relative to shuffled corpora. Child-directed language was found to be more associative, repetitive and consistent than adult-directed language. Moreover, these statistical properties of child-directed language better predicted word acquisition than the same statistics in adult-directed language. Word frequency and repetitions were the best predictors within word classes (nouns, verbs, adjectives and function words). For all word classes combined, associative structure, contextual diversity and word repetitions best predicted language acquisition. These results support the hypothesis that child-directed language is structured in ways that facilitate language acquisition.

This study reports on language outcomes at eight years from the Bucharest Early Intervention Project, a randomized controlled study of foster care. We previously have shown that children placed in foster care by age two have substantially stronger preschool language outcomes than children placed later and children remaining in institutional care. One hundred and five children participated in the current study, fifty-four originally assigned to foster care and fifty-one to continued institutional care. Even though current placements varied, children originally in foster care had longer sentences and stronger sentence repetition and written word identification. Children placed in foster care by age two had significant advantages in word identification and nonword repetition; children placed by age 1 ; 3 performed equivalently to community peers. The results show the continuing adverse effects of early poor institutional care on later language development and the key importance of age of placement in a more optimal environment.

The interpretation of floating quantifiers in Japanese requires knowledge of hierarchical phrase structure. However, the input to children is insufficient or even misleading, as our analysis indicates. This presents an intriguing question on learnability: do children interpret floating quantifiers based on a structure-dependent rule which is not obvious in the input or do they employ a sentence comprehension strategy based on the available input? Two experiments examined four- to six-year-old Japanese-speaking children for their interpretations of floating quantifiers in SOV and OSV sentences. The results revealed that no child employed a comprehension strategy in terms of the linear ordering of constituents, and most five- and six-year-olds correctly interpreted floating quantifiers when word-order difficulty was reduced. These facts indicate that children's interpretation of floating quantifiers is structurally dependent on hierarchical phrase structure, suggesting that this knowledge is a part of children's grammar despite the insufficient input available to them.

In this article we report two studies: a detailed longitudinal analysis of errors in wh-questions from six German-learning children (age 2 ; 0–3 ; 0) and an analysis of the prosodic characteristics of wh-questions in German child-directed speech. The results of the first study demonstrate that German-learning children frequently omit the initial wh-word. A lexical analysis of wh-less questions revealed that children are more likely to omit the wh-word was (‘what’) than other wh-words (e.g. wo ‘where’). In the second study, we performed an acoustic analysis of sixty wh-questions that one mother produced during her child's third year of life. The results show that the wh-word was is much less likely to be accented than the wh-word wo, indicating a relationship between children's omission of wh-words and the stress patterns associated with wh-questions. The findings are discussed in the light of discourse–pragmatic and metrical accounts of omission errors.

The talk children hear from their primary caregivers predicts the size of their vocabularies. But children who spend time with multiple individuals also hear talk that others direct to them, as well as talk not directed to them at all. We investigated the effect of linguistic input on vocabulary acquisition in children who routinely spent time with one vs. multiple individuals. For all children, the number of words primary caregivers directed to them at age 2 ; 6 predicted vocabulary size at age 3 ; 6. For children who spent time with multiple individuals, child-directed words from all household members also predicted later vocabulary and accounted for more variance in vocabulary than words from primary caregivers alone. Interestingly, overheard words added no predictive value to the model. These findings suggest that speech directed to children is important for early word learning, even in households where a sizable proportion of input comes from overheard speech.

Speech perception involves the integration of auditory and visual articulatory information, and thus requires the perception of temporal synchrony between this information. There is evidence that children with specific language impairment (SLI) have difficulty with auditory speech perception but it is not known if this is also true for the integration of auditory and visual speech. Twenty Spanish-speaking children with SLI, twenty typically developing age-matched Spanish-speaking children, and twenty Spanish-speaking children matched for MLU-w participated in an eye-tracking study to investigate the perception of audiovisual speech synchrony. Results revealed that children with typical language development perceived an audiovisual asynchrony of 666 ms regardless of whether the auditory or visual speech attribute led the other one. Children with SLI only detected the 666 ms asynchrony when the auditory component followed the visual component. None of the groups perceived an audiovisual asynchrony of 366 ms. These results suggest that the difficulty of speech processing by children with SLI would also involve difficulties in integrating auditory and visual aspects of speech perception.