This research examines phonological neighbourhoods in the lexicons of children acquiring English. Analyses of neighbourhood densities were done on children's earliest words and on a corpus of spontaneous speech, used to measure neighbours in the target language. Neighbourhood densities were analyzed for words created by changing segments in word-onset position (rhyme neighbours as in pin/bin), vowel position (consonant neighbours as in pin/pan/) and word-offset position (lead neighbours as in pin/pit). Results indicated that neighbours in children's early lexicons are significantly more often distinguished in word-onset position (rhyme neighbours) and significantly less often distinguished in word-offset position (lead neighbours). Moreover, patterns in child language are more extreme than in the target language. Findings are discussed within the PRIMIR framework (Processing Rich Information from Multidimensional Interaction Representations; Werker & Curtin, 2005). It is argued that early perceptual sensitivity aids lexical acquisition, supporting continuity across speech perception and lexical acquisition.

One important mechanism suggested to underlie the acquisition of grammar is rule learning. Indeed, infants aged 0 ; 7 are able to learn rules based on simple identity relations (adjacent repetitions, ABB: “wo fe fe” and non-adjacent repetitions, ABA: “wo fe wo”, respectively; Marcus et al., 1999). One unexplored issue is whether young infants are able to process both adjacent and non-adjacent repetitions. As the previous studies always compared the two types of repetition structures directly, the ability to learn only one of them was sufficient for successful discrimination in these tasks. The present study reports two experiments, in which we test the ability of infants aged 0 ; 7 to discriminate adjacent and non-adjacent repetition structures against random controls (ABB vs. ABC and ABA vs. ABC). We show that, contrary to some previous proposals, infants aged 0 ; 7 successfully discriminate both repetition types from random controls, but show no spontaneous preference for either of them.

Infant temperament characteristics of activity level, task persistence and affect were measured in an eight-month longitudinal study of eight children. Discourse and pragmatic features of their mothers' speech, specifically total number of utterances and use of self-repetitions, directives and attention-getting devices, were also monitored. Pearson correlation analysis suggested complex interactions between maternal speech and infant temperament. In some cases a maternal speech pattern appears to maintain an infant temperament characteristic. In others, a child characteristic appears to maintain a maternal speech form. The results are used to argue that non-linguistic child behaviours may influence maternal speech and deserve further attention in investigations of the link between maternal speech and child-language development.

In full passive sentences such as The cat was kicked by the dog, the patient (cat) is promoted to subject and the agent is demoted to the by-phrase. Children 2;10 to 4;7 years (mean 3;6) who were taught the form with animate patients and animate agents (The baby is being picked up by the girl) were better able to produce and comprehend passives than children taught with inanimate patients and animate agents (The flower is being picked up by the girl). The finding of comparable post-teaching performance in children taught with perceptually salient (coloured) VS. nonsalient patients argues against a salience explanation for the patient animacy effect. Moreover, equal access to word forms for animate and inanimate nouns did not reduce the effect. The animacy effect is consistent with claims that ‘perspective’ is the cognitive counterpart to the formal category of subject; and, conversely, inconsistent with attempts to understand language acquisition in terms of a language system that operates in isolation from other facets of human cognition.

Rapid acquisition of linguistic categories or constructions is sometimes regarded as evidence of innate knowledge. In this paper, we examine Polish children's early understanding of an idiosyncratic, language-specific construction involving the instrumental case – which could not be due to innate knowledge. Thirty Polish-speaking children aged 2 ; 6 and 3 ; 2 participated in a elicited production experiment with novel verbs that were demonstrated as taking nouns in the instrumental case as patients. Children heard the verbs in sentences with either masculine or feminine nouns (which take different endings in the instrumental case), and were tested with new nouns of the same and of the opposite gender. In both age groups, a substantial majority of children succeeded in generalizing from one gendered form of the instrumental case to the other (especially to the masculine), thus indicating that they have some kind of abstract understanding of the instrumental case in this construction. This relatively early abstract knowledge of an idiosyncratic construction casts doubt on the view that early acquisition requires innate linguistic knowledge.

The communicative interactions of 15 dyads of four- to five-year-olds during pretend play involving routine, or scripted, events were investigated as a function of the children's knowledge of the scripts. Measures of the quantity and quality of interaction and the strategies that the children used to establish mutual knowledge (i.e. assess and adapt to their discourse partner's level of expertise), which is essential to good communication, were examined. Each dyad participated in a MATCHED condition (both members had extensive knowledge of the script) and a MISMATCHED condition (one member had extensive script knowledge and the other did not). Shared script knowledge facilitated communicative interactions, as indicated by more topic maintenance and fewer requests for clarification in the matched condition than in the mismatched condition. The children attempted to establish mutual knowledge more frequently in the mismatched condition than in the matched condition and, moreover, mutual knowledge establishment was related to the children's communicative effectiveness.

The present study investigates whether five-to-six-year-old children with Williams syndrome (N=8) can form new object categories based on naming information alone, and compares them with five groups of typically developing children aged 2;0 to 6;0 (N=34 children). Children were presented with triads of dissimilar objects; all objects in a triad were labelled, two of them with the same pseudoname. Name-based categorization was evaluated through object selection. Performance was above chance level for all groups. Performance reached a ceiling at about 4;0 for the typically developing children. For the children with Williams Syndrome, performance remained below chronological age level. The present results are discussed in light of previous findings of a failure to perform name-based categorization in younger children with Williams syndrome and the persistent asynchrony between cognitive and lexical development in this disorder.

Children tend to regularize their productions when exposed to artificial languages, an advantageous response to unpredictable variation. But generalizations in natural languages are typically conditioned by factors that children ultimately learn. In two experiments, adult and six-year-old learners witnessed two novel classifiers, probabilistically conditioned by semantics. Whereas adults displayed high accuracy in their productions – applying the semantic criteria to familiar and novel items – children were oblivious to the semantic conditioning. Instead, children regularized their productions, over-relying on only one classifier. However, in a two-alternative forced-choice task, children's performance revealed greater respect for the system's complexity: they selected both classifiers equally, without bias toward one or the other, and displayed better accuracy on familiar items. Given that natural languages are conditioned by multiple factors that children successfully learn, we suggest that their tendency to simplify in production stems from retrieval difficulty when a complex system has not yet been fully learned.

The written compositions of 11-year-olds in the National Child Development Study were analysed using the T-unit length (Hunt 1965) as a measure of syntactic maturity, and composition length as a measure of productivity. Only a weak association was found between mean T-unit length (MTUL) and composition length. There were no statistically significant regional differences in either composition length or MTUL. There were statistically significant sex and social class differences in composition length but not in MTUL. Composition length was associated with Reading Comprehension, General Ability test scores, and teachers' ratings of certain scholastic aptitudes. MTUL was associated only slightly or not at all with these measures. The results are discussed in relation to cognitive and linguistic development.

We investigate how Tamil- and Dutch-speaking adults and four- to five-year-old children use caused posture verbs (‘lay/stand a bottle on a table’) to label placement events in which objects are oriented vertically or horizontally. Tamil caused posture verbs consist of morphemes that individually label the causal and result subevents (nikka veyyii ‘make stand’; paDka veyyii ‘make lie’), occurring in situational and discourse contexts where object orientation is at issue. Dutch caused posture verbs are less semantically transparent: they are monomorphemic (zetten ‘set/stand’; leggen ‘lay’), often occurring in contexts where factors other than object orientation determine use. Caused posture verbs occur rarely in Tamil input corpora; in Dutch input, they are used frequently. Elicited production data reveal that Tamil four-year-olds use infrequent placement verbs appropriately whereas Dutch children use high-frequency placement verbs inappropriately even at age five. Semantic transparency exerts a stronger influence than input frequency in constraining children's verb meaning acquisition.

This study charts the development of the genitive masculine inflection, one of the most irregular parts of the Polish case-marking system. 72 Polish children aged from 2;3 to 10;8 participated in a nonce word production experiment testing their ability to supply the genitive form and their sensitivity to the semantic factors determining the choice of ending. Results indicate that productivity, or the ability to supply the inflected form of some nonce words, emerges early: 78% of the two-year-olds were able to inflect at least one test item. However, mastery, or the ability to consistently supply the correct ending, takes considerably longer to develop, and adultlike levels of provision are not reached until about age 10;0.

Fernald and her colleagues have argued for the universality of prosodic modifications in speech addressed to infants (e.g. Fernald, 1987; Fernald, Taeschner, Dunn, Papousek, de Boysson-Bardies & Fukui, 1989). An alternative proposal in Bernstein-Ratner & Pye (1984) and Pye (1986) argues that speech modifications to children are the result of a set of conventions that may vary from culture to culture. This note presents arguments against Fernald and in support of the cultural account of prosodic modifications to infants and children. First, in response to criticisms in Fernald et al., data are presented which defend the conclusion in Bernstein-Ratner & Pye that Quiché mothers show less prosodic modification to children than do mothers in other cultures studied to date. Second, data used to support the universal position in Fernald (1987) on adult identification of infant affective states are reinterpreted and shown to be equally interpretable as the result of a set of culturally transmitted rules.

We report a study of the acquisition of colour terms by speakers of Setswana, the language of Botswana in Southern Africa. This was carried out as a test of Berlin & Kay's theory of colour term universals, on a language with less than the maximum complement of eleven basic colour terms, and in order to document changes in Setswana under the impact of economic development. Seventy-seven five- to nine-year-olds were studied on two colour tasks: elicited lists and colour naming. In general the data were consistent with Berlin & Kay's theory: the rank order of frequency of correct use of colour terms was similar to the order of the Berlin & Kay hierarchy; and primary colour terms were offered more frequently and were more likely to be used correctly than secondary colour terms. The use of English colour terms was prevalent, especially amongst the younger groups, but they functioned as substitutes for Setswana terms, rather than as a means to fill the vacant basic colour term slots.

Two lawful relationships involving word-initial onset clusters have been advanced in the acquisition literature; namely, that clusters imply affricates, and that liquid clusters imply a liquid distinction. This study evaluated and extended the validity of these implicational laws in a population of 110 children (aged 3;0 to 8;6) with functional phonological delays who contributed extended speech samples for computational analyses. Results indicated that, for the most part, the composition of children's sound systems were in compliance with the proposed laws; however, there were noted asymmetries and apparent exceptions in the data. The asymmetries motivated an integration of the two laws to reveal a pattern of segmental–prosodic cyclicity consistent with deterministic models of phonological acquisition. The apparent exceptions highlighted the relevance of independent methodologies and offered a potential theoretical alternative with the Resolvability Principle as directions for future research.

This study investigates the pitch properties of infant-directed speech (IDS) specific to word-learning contexts in which mothers introduce unfamiliar words to children. Using a semi-spontaneous story-book telling task, we examined (1) whether mothers made distinctions between unfamiliar and familiar words with pitch in IDS compared to adult-directed speech (ADS); (2) whether pitch properties change when mothers address children from 18 to 24 months; and (3) how Mandarin Chinese and Dutch IDS differ in their pitch properties in word-learning contexts. Results show that the mean pitch of Mandarin Chinese IDS was already ADS-like when children were 24 months, but Dutch IDS remained exaggerated in pitch at the same age. Crucially, Mandarin Chinese mothers used a higher pitch and a larger pitch range in IDS when introducing unfamiliar words, while Dutch mothers used a higher pitch specifically for familiar words. These findings contribute to the language-specificity of prosodic input in early lexical development.

Will adults whose native language is English and children whose native language is Spanish follow the same strategies in acquiring the category of noun gender and its functions in Spanish? This investigation shows that there are significant differences in first- and second-language acquisition. Performance on five tasks eliciting responses containing gender agreement was measured for two groups. Results suggest that there is a developmental progression in acquisition of noun gender for both groups. Nevertheless, on tasks containing grammatical and/or semantic conflict, even the linguistically least-experienced adults reflected correct, adult-like strategies for Spanish gender agreement, whereas only the oldest children performed in this manner.

Diary studies of English, Hebrew and Portuguese have led to debate on whether there is directionality in children's transitivity errors – that is, whether children are as likely to coin intransitives from transitives (*Bert knocked down) as they are transitives from intransitives (*I falled my cup). The judgements made by 3- and 4-year-olds showed a strong bias in favour of innovative transitives in English. It is argued that this bias results from children's preference for prototypical, highly transitive descriptions of events.

Children are frequently confronted with so-called ‘test questions’. While genuine questions are requests for missing information, test questions ask for information obviously already known to the questioner. In this study we explored whether two-year-old children respond differentially to one and the same question used as either a genuine question or as a test question based on the situation (playful game versus serious task) and attitude (playful ostensive cues versus not). Results indicated that children responded to questions differently on the basis of the situation but not the expressed attitude of the questioner. Two-year-old children thus understand something of the very special communicative intentions behind test questions.

Recent studies on the acquisition of semantics have argued that knowledge of the universal quantifier is adult-like throughout development. However, there are domains where children still exhibit non-adult-like universal quantification, and arguments for the early mastery of relevant semantic knowledge do not explain what causes such non-adult-like interpretations. The present study investigates Japanese four- and five-year-old children's atypical universal quantification in light of the development of cognitive control. We hypothesized that children's still-developing cognitive control contributes to their atypical universal quantification. Using a combined eye-tracking and interpretation task together with a non-linguistic measure of cognitive control, we revealed a link between the achievement of adult-like universal quantification and the development of flexible perspective-switch. We argue that the development of cognitive control is one of the factors that contribute to children's processing of semantics.