There is considerable debate about whether early vocalizations mimic the target language and whether prosody signals emergent intentional communication. A longitudinal corpus of four Catalan-babbling infants was analyzed to investigate whether children use different prosodic patterns to distinguish communicative from investigative vocalizations and to express intentionality. A total of 2,701 vocalizations from 0;7 to 0;11 were coded acoustically (by marking pitch range and duration), gesturally, and pragmatically (by marking communicative status and specific pragmatic function). The results showed that communicative vocalizations were shorter and had a wider pitch range than investigative vocalizations and that these patterns in communicative vocalizations depended on the intention of the vocalizations: requests and expressions of discontent displayed wider pitch range and longer duration than responses or statements. These results support the hypothesis that babbling children can successfully use a set of prosodic patterns to signal intentional speech.

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.

The impact of input frequency (IF) and functional load (FL) of segments in the ambient language on the acquisition order of word-initial consonants is investigated. Several definitions of IF/FL are compared and implemented. The impact of IF/FL and their components are computed using a longitudinal corpus of interactions between thirty Dutch-speaking children (age range: 0 ; 6–2 ; 0) and their primary caretaker(s). The corpus study reveals significant correlations between IF/FL and acquisition order. The highest predictive values are found for the token frequency of segments, and for FL computed on minimally different word types in child-directed speech. Although IF and FL significantly correlate, they do have a different impact on the order of acquisition of word-initial consonants. When the impact of IF is partialed out, FL still has a significant correlation with acquisition order. The reverse is not true, suggesting that the acquisition of word-initial consonants is mainly influenced by their discriminating function.

The present study investigates whether four- and six-year-old children use pragmatic competence as a criterion for learning from someone else. Specifically, we ask whether children use others' adherence to Gricean maxims to determine whether they will offer valid labels for novel objects. Six-year-olds recognized adherence to the maxims of quality and relation and subsequently trusted the labels provided by a maxim adherer. Four-year-olds displayed this pattern when judging adherence to quality but not relation. A linear regression revealed that children's ability to identify maxim adherers predicted their ability to choose the correct object during word-learning trials. This research demonstrates that children use others' pragmatic history when judging the reliability of the information they offer.

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.

Previous studies on children's pragmatic abilities have tended to focus on just one pragmatic phenomenon and one expressive means at a time, mainly concentrating on comprehension, and overlooking the production side. We assessed both comprehension and production in relation to several pragmatic phenomena (simple and complex standard communication acts, irony, and deceit) and several expressive means (linguistic, extralinguistic, paralinguistic). Our study involved 390 Italian-speaking children divided into three age groups: 5;0–5;6, 6;6–7;0, and 8;0–8;6. Children's performance on all tasks improved with their age. Within each age group, children responded more accurately to tasks involving standard communication than to those involving deceit and irony, across all expressive means and for both comprehension and production. Within each pragmatic phenomenon, children responded more accurately to simple acts than to complex ones, regardless of age group and expressive means, i.e., linguistic or extralinguistic. Overall results fit well with the Cognitive Pragmatics theory (Bara, 2010).

This study tests the hypothesis that developmental dyslexia is (partly) caused by a deficit in implicit sequential learning, by investigating whether infants at familial risk of dyslexia can track non-adjacent dependencies in an artificial language. An implicit learning deficit would hinder detection of such dependencies, which mark grammatical relations (e.g. between ‘is’ and ‘-ing’ in ‘she is happily singing’). In a head-turn experiment with infants aged 1;6, family risk and typically developing infants were exposed to one of two novel languages containing dependencies of the type a-X-c, b-X-d or a-X-d, b-X-c, with fixed first and third elements and twenty-four different X elements. During test, typically developing children listened longer to ungrammatical strings (i.e. that did not correspond to their training language). However, family-risk children did not discriminate between grammatical and ungrammatical strings, indicating deficient implicit learning. The implications of these findings in relation to dyslexia and other language-based disorders are discussed.

We studied spontaneous speech noun-phrase production in eight French-speaking children with SLI (aged 5 ; 0 to 5 ; 11) and controls matched on age (4 ; 10 to 5 ; 11) or MLU (aged 3 ; 2 to 4 ; 1). Results showed that children with SLI prefer simple DP structures to complex ones while producing more substitution and omission errors than controls. The three groups also showed distinct error patterns. Children with SLI appeared to have difficulty with phonological processes involved in liaison, elision, and contraction, whereas control children tended to make more lexical errors. These data support models of reduced morphosyntactic and syntactic abilities in this population, and suggest that morphophonological processes should also be integrated into descriptive models of SLI.

Neighbourhood Density (ND) and Phonotactic Probability (PP) influence word learning in children. This influence appears to change over development but the separate developmental trajectories of influence of PP and ND on word learning have not previously been mapped. This study examined the cross-sectional developmental trajectories of influence of PP and ND on fast-mapping in thirty-eight English-speaking children aged 3 ; 01–5 ; 02, in a task varying PP and ND orthogonally. PP and ND exerted separable influences on fast-mapping. Overall, low ND supported better fast-mapping. The influence of PP changed across the developmental trajectory, ‘switching’ from a high to a low PP advantage. A potential explanation for this ‘switch’ is advanced, suggesting that it represents functional reorganization in the developing lexicon, which emerges from changes in the developing lexicon, as phonological knowledge is abstracted from lexical knowledge, over development.

A large body of research shows that vocabulary does not develop independently of grammar, representing a better predictor of the grammatical complexity of toddlers' utterances than age. This study examines for the first time the characteristics of vocabulary and grammar development in Slovenian-speaking infants and toddlers using the Slovenian adaptation of the MacArthur-Bates Communicative Development Inventories (CDI). The sample included 512 Slovenian-speaking infants and toddlers aged 0 ; 8 to 2 ; 6. The findings suggest that between age 0 ; 8 and 2 ; 6 the development of vocabulary is best described using a quadratic function. The results also show that nouns predominate in the vocabularies of infants and toddlers of various ages; as they age and with the increasing size of their vocabularies, the share of interjections decreases and the share of verbs and adjectives increases. The size of vocabulary was also found to be related to the grammatical structure of toddlers' utterances.

It is not well understood how grammar emerges in very-low-birth-weight (VLBW) children. The main aim of the present study was to gain information on the emergence of grammar in this group at 2 ; 0. The Finnish version of the Communicative Development Inventory was used to collect data from VLBW children (N = 156) and full-term controls (N = 146). At a group level, the grammatical skills of the VLBW children were significantly weaker than those of the controls. However, when the effect of lexicon size and premature birth on the emergence of grammar was analyzed in detail, few significant differences were found between the groups. The results suggest that even though grammar emerges more slowly for the VLBW children, it emerges in a manner comparable to that of the controls, when the effect of lexicon size is taken into consideration.

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.

Children's assignment of novel words to nameless objects, over objects whose names they know (mutual exclusivity; ME) has been described as a driving force for vocabulary acquisition. Despite their ability to use ME to fast-map words (Preissler & Carey, 2005), children with autism show impaired language acquisition. We aimed to address this puzzle by building on studies showing that correct referent selection using ME does not lead to word learning unless ostensive feedback is provided on the child's object choice (Horst & Samuelson, 2008). We found that although toddlers aged 2;0 at risk for autism can use ME to choose the correct referent of a word, they do not benefit from feedback for long-term retention of the word–object mapping. Further, their difficulty using feedback is associated with their smaller receptive vocabularies. We propose that difficulties learning from social feedback, not lexical principles, limits vocabulary building during development in children at risk for autism.

This study examined two facets of the use of social cues for early word learning in parent–child dyads, where children had an Autism Spectrum Disorder (ASD) or were typically developing. In Experiment 1, we investigated word learning and generalization by children with ASD (age range: 3;01–6;02) and typically developing children (age range: 1;02–4;09) who were matched on language ability. In Experiment 2, we examined verbal and non-verbal parental labeling behaviors. First, we found that both groups were similarly able to learn a novel label using social cues alone, and to generalize this label to other representations of the object. Children who utilized social cues for word learning had higher language levels. Second, we found that parental cues used to introduce object labels were strikingly similar across groups. Moreover, parents in both groups adapted labeling behavior to their child's language level, though this surfaced in different ways across groups.

The current study used growth curve analysis to study the role of input during the acquisition of the English causal connective because and its German counterpart weil. The corpora of five German and five English children and their adult caretakers (age range 0;10–4;3) were analyzed for the amount as well as for the type of connective use – imitated, elicited, and independent. The growth curves showed that children's elicited use developed faster than their independent use; imitations were rare. Adult connective input was not found to function as a scaffold of children's connective use. Rather, the adult why/warum-questions played an important role in the acquisition of because and weil. In turn, children also used why/warum-questions to elicit causal responses from their caretakers, which shows that children were responsible for a great part of their own input.

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.

For sixty-seven children with ASD (age 1;6 to 5;11), mean Total Vocabulary score on the Language Development Survey (LDS) was 65·3 words; twenty-two children had no reported words; and twenty-one children had 1–49 words. When matched for vocabulary size, children with ASD and children in the LDS normative sample did not differ in semantic category or word-class scores. Q correlations were large when percentage use scores for the ASD sample were compared with those for samples of typically developing children as well as children with vocabularies <50 words. The 57 words with the highest percentage use scores for the ASD children were primarily nouns, represented a variety of semantic categories, and overlapped substantially with the words having highest percentage use scores in samples of typically developing children as well as children with lexicons of <50 words. Results indicated that the children with ASD were acquiring essentially the same words as typically developing children, suggesting delayed but not deviant lexical composition.

This study investigated cross-linguistic influence in acquisition of a second lexicon, evaluating Samoan–English sequentially bilingual children (initial mean age 4 ; 9) during their first 18 months of school. Receptive and Expressive Vocabulary tasks evaluated acquisition of four word types: cognates, matched nouns, phrasal nouns and holonyms. Each word type had varying phonological and conceptual difference between Samoan (L1) and English (L2). Results highlighted conceptual distance between L1 and L2 as a key factor in L2 lexical acquisition. The children acquired L2 lexical items earlier if their conceptual representation was similar to that of L1. Words with greater conceptual distance between L1 and L2 emerged more slowly. This suggests that L1 knowledge influences L2 lexical consolidation for sequential bilinguals. Words that require a conceptual shift from L1 take longer to consolidate and strengthen within the L2 lexicon.

English-learning children have been shown to reliably use cues from argument structure in learning verbs. However, languages pair overtly expressed arguments with verbs to varying extents, raising the question of whether children learning all languages expect the same, universal mapping between arguments and relational roles. Three experiments examined this question by asking how strongly early-learned verbs by themselves, without their corresponding explicitly expressed arguments, point to ‘conceptual arguments’ – the relational roles in a scene. Children aged two to four years and adult speakers of two languages that differ structurally in terms of whether the arguments of a verb are explicitly expressed more (English) or less (Tamil) frequently were compared in their mapping of verbs, presented without any overtly expressed arguments, to a range of scenes. The results suggest different developmental trajectories for language learners, as well as different patterns of adult interpretation, and offer new ways of thinking about the nature of verbs cross-linguistically.