The aim of this study is to examine how caretakers speak to young children in a day-care centre and particularly to investigate how they adjust their language, according to children's age and to size of groups. Five Italian teachers were observed, each one during six different sessions. Children's ages were 0;10–1;2 and 2;6–3;0. The number of children varied from a rather large group (seven children) to a small group (three children) to a single child. Language was taperecorded during free-play sessions of ten minutes. Context was noted by two observers. Transcripts were analysed according to structural features (syntactical complexity, redundancy, type-token ratio, speed) and functional features (proportion of utterances with different purpose: control and organization of child behaviour, empathy, conversation and teaching). Results show some significant differences in structure and function according to children's age and group size.

Reports that infants imitate the vocal pitch characteristics of adult caregivers (e.g. Lewis, 1936/1951) include Lieberman's (1967; Lieberman, Ryalls & Rabson, 1982) claim that infants differentially adjust their vocal pitch or fundamental frequency (f0) towards that of their caregivers, resulting in higher mean pitch when interacting with mothers than when interacting with fathers. However, a recent cross-sectional study of infants at ages 0;8 to 0;9 and 1;0 failed to find evidence of differential pitch adjustment toward male and female caregivers (Siegel, Cooper, Morgan & Brennesie-Sarshad, 1990). A more sensitive test of Lieberman's claims would be to use a longitudinal design, with spontaneous recording sessions repeated over many months. The current study presents data from a longitudinal case study of an infant recorded at ages 0;3, 0;7, 0;10, 1;3 and 1;5 interacting with each of her parents in spontaneous play sessions and in isolated play. The infant in our study did not demonstrate significant adjustment of her vocal pitch in the direction of either parent. However, we did find evidence for consistent adjustment by the parents, in accord with the literature on infant-directed speech and mother–infant dyadic interactions, which suggest that the parents adjusted their behaviour to suit the infant more than vice versa.

This work aims to analyse the specific contribution of social abilities (here considered as the capacity for attributing knowledge to others) in a particular communicative context. 74 normally developing children (aged 3;4 to 5;9, M=4·6) were given two Theory of Mind (ToM) tasks, which are considered to assess increasing complexity levels of epistemic state attribution: Attribution of knowledge-ignorance (Pillow, 1989; adapted by Welch-Ross, 1997) and Understanding of False-belief (Baron Cohen, Leslie & Frith, 1985). Subjects were paired according to their age and level of performance in ToM tasks. These dyads participated in a referential communication task specially designed for this research. The resulting communicative interchanges were analysed using a three-level category system (pragmatic functions, descriptive accuracy, and ambiguity of messages). The results showed significant differences among subjects with different levels of social comprehension regarding the type of communicative resources used by them in every category level. In particular, understanding of false belief seems to be the most powerful predictor of changes in the children’s development of communicative competence.

This paper gives an account of the transition from one-word to multiword utterances based on the productions of one child from age 1;5.23 to 1;8.15 in spontaneous interaction with her mother. The authors' interpretation of the observed development emphasizes: (1) the initial dissociation and later co-ordination of temporal chaining of elements on the one hand and meaning-relatedness between elements on the other; and (2) the psychological importance of repetition patterns for the change from single-word functioning to meaning-related and temporally-chained multi-word utterances, i.e. utterances that show the duality of patterning characteristic of human language.

Using an infant speech identification (ISI) procedure, English language environment infants, two- and six-year-old children, and adults were tested for their identification of sounds on a native (voiced/voiceless bilabial stop) and a non-native (prevoiced/voiced bilabial stop) speech continuum. Categorical perception of the two contrasts diverged as a function of age, increasing for the native contrast and decreasing for the non-native between two and six years. In Experiment 2, subjects of the same four ages were tested for their identification of a continuum of harmonic tones varying in pitch. Comparison of the results of Experiment i with the essentially continuous perception of this pitch continuum supports the view that the perception of the native contrast becomes more categorical with age, while perception of the non-native contrast becomes less categorical, especially at six years. Experiment 3, in which adults were tested on the three continua with a multi-trial open set procedure, demonstrated that results with the ISI procedure in Experiments 1 and 2 are comparable to results with more traditional methods. The results of the three experiments are discussed in terms of the role of specific linguistic experience in the development of categorical speech perception.

This study considers the much-debated markedness and structural status of word-initial /s/-sequences in English by examining the development of KR (male, age 3;6) who has a phonological disorder. Three points in time are discussed: (1) when all initial consonant sequences are reduced to singletons; (2) when only initial /s/-sequences surface correctly; and (3) when all initial consonant sequences surface correctly. While these production patterns are common across developing systems, few accounts have addressed them in terms of structure or markedness. Toward that end, it is argued that KR's /s/-sequences surface as ADJUNCTS, rather than complex onsets. This is explained within optimality theory, whereby high-ranking markedness constraints prevent complex onsets but not adjuncts. The account offers an explanation for consonant sequence asymmetries within and across grammars, allowing for differing representations for /s/-sequences across speakers and for variation exhibited in children's productions. A typology of possible grammars is therefore offered, and clinical implications are considered.

Research on the development of efficiency in spoken language understanding has focused largely on middle-class children learning English. Here we extend this research to Spanish-learning children (n=49; M=2;0; range=1;3–3;1) living in the USA in Latino families from primarily low socioeconomic backgrounds. Children looked at pictures of familiar objects while listening to speech naming one of the objects. Analyses of eye movements revealed developmental increases in the efficiency of speech processing. Older children and children with larger vocabularies were more efficient at processing spoken language as it unfolds in real time, as previously documented with English learners. Children whose mothers had less education tended to be slower and less accurate than children of comparable age and vocabulary size whose mothers had more schooling, consistent with previous findings of slower rates of language learning in children from disadvantaged backgrounds. These results add to the cross-linguistic literature on the development of spoken word recognition and to the study of the impact of socioeconomic status (SES) factors on early language development.

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.

Although questions vary considerably with respect to the responses appropriate to them and the motivations intrinsic to them, little attention has yet been given to the potential effects of these factors on the power of questions to perform turn-allocating and response-eliciting functions. The present study attempts to clarify how such variables as motivation, constraint, difficulty and function may affect the child's responsiveness to mother questions. Results suggest that functionally defined question types are differentiable not only by their relative power to elicit a response from the child, but also by the manner in which they are presented. Implications of these results in the context of mother–child conversation and its effects are considered.

Microanalyses of unstructured videotaped interactions of three mother-infant dyads revealed dramatic shifts in dyadic vocalization patterns from primarily overlapping to primarily alternating. Maximal overlapping vocalization appeared between 7 and 13 weeks for the different dyads, and subsequent alternation predominance peaked between 12 and 18 weeks. The findings are compared with prior work which had not found alternation predominance and reasons for the difference are suggested. The early emergence of a sequence of predominantly overlapping vocalization followed by predominantly alternating vocalization may be linked to the concomitant development of multimodal sensory-sensory and sensory-motor integration. If so, then the emergent patterns reflect increased potential for co-ordination within the dyad, which may be capitalized upon by the mother and by the infant.

Clark's (1973) hypothesis about the acquisition of semantics proposed that young children learn the meanings of words component by component, and that, within any given semantic field, they acquire the full adult meanings for the semantically simpler terms before they acquire the semantically more complex ones. The semantic field investigated in the present study was that of kinship terms. A new analysis of kin terms, employing relational components, was used to predict the relative order of acquisition of the terms. Definitions of 15 kin terms were elicited from children aged 3;5–8;10. The data showed that semantic complexity played an important role in determining the order of acquisition, and thus provided support for both the relational analysis of kin terms and the semantic acquisition hypothesis.

This article challenges the position of Clark (1988) with regard to Contrast. The evidence cited in support of this theory from adult languages is far from clear, and the evidence coming from child language admits of alternative explanations. In addition, the ‘logic’ of assuming Contrast leads to insurmountable difficulties in the acquisition of irregular forms and allomorphs. An alternative to Contrast is proposed. This draws on the drive towards the adult system, the development of non-linguistic concepts, the acquisition of language in context, and the use of the Co-operative Principle by participants in conversational exchanges to account for those features of language and language acquisition that Contrast was designed to explain.

A total of 48 male infants experienced either conversational turn-taking or random responsiveness of their mothers when aged 0;3 and 0;4. In both periods, the infant's rate of vocalizing was not significantly influenced by the contingency of the mother's response, but contingency altered the temporal parameters of the infant's vocal pattern. Infants tended to produce more bursts or packets of vocalizations when the mother talked to the infant in a random pattern. When the infants were aged 0;3 such bursts occurred most often at intervals of 0·5–1·5 sec whereas when they were aged 0;4 they took place most frequently at significantly longer intervals, of 1·0–2·0. The difference corresponded to the difference between intervals with which the mother responded contingently to vocalizations of the infant at 0;3 and at 0;4. While the intervals (between the onset of the infant's vocalization and the onset of the mother's vocalization) rarely exceeded 0·5 sec when the infant was aged 0;3, they were mostly distributed between 0·5 and 1·0 sec when he was aged 0;4. After vocalizing spontaneously, the infant tended to pause as if to listen for a possible vocal response from the mother. In the absence of a response, he vocalized repeatedly. The intervals between the two consecutive vocalizations were changed flexibly by the infant according to his recent experience of turn-taking with the mother.

This investigation focuses on the development of intonation patterns in four Catalan-speaking children and two Spanish-speaking children between 0 ; 11 and 2 ; 4. Pitch contours were prosodically analyzed within the Autosegmental Metrical framework in all meaningful utterances, for a total of 6558 utterances. The pragmatic meaning and communicative function were also assessed. Three main conclusions arise from the results. First, the study shows that the Autosegmental Metrical model can be successfully used to transcribe early intonation contours. Second, results reveal that children's emerging intonation is largely independent of grammatical development, and generally it develops well before the appearance of two-word combinations. As for the relationship between lexical and intonational development, the data show that the emergence of intonational grammar is related to the onset of speech and the presence of a small lexicon. Finally, we discuss the implications of these results for the biological hypothesis of intonational production.

Research on early mother-child interaction has documented the crucial role affect plays in the content and modulation of early interactions. For hearing mothers, voice quality is considered to be the single most informative channel for affective expression. For deaf caregivers who use American Sign Language (ASL), the vocal channel is unavailable, and facial expression is critically important. Not only do facial behaviours signal affective and communicative information, but specific facial behaviours also function as obligatory grammatical markers. This multifunctionality of facial expression presents a dilemma for deaf parents signing to their toddlers as these two systems potentially compete for expression on the face. This study addresses how affective facial expression interacts with the linguistic forms in ASL motherese. To address this issue, we present data from both cross-sectional and longitudinal videotaped interaction from a total of 15 deaf mothers signing with their deaf toddlers (ages 0;9–2;8). Using Ekman & Friesen's Facial Action Coding System (FACS) (1978) we analysed child-directed maternal wh- questions. Because they are frequent in early discourse, AND they require furrowed brows which also signal anger and puzzlement, wh- questions represent an ideal context to address the potential conflict of grammatical and affective facial expression in ASL motherese. Our studies indicate a shift from affect to grammar at about the child's second birthday. These findings shed new insight on the nature and possible role of input on the language acquisition process.

Many comprehension studies have shown that children as late as age 6 ; 6 misinterpret object pronouns as co-referring with the referential subject about half the time. A recent review of earlier experiments testing children's interpretation of object pronouns in sentences with quantified subjects (Elbourne, 2005) also suggests that there is a ‘Pronoun Interpretation Problem’. In contrast, two experiments addressing English children's pronoun production (Bloom, Barss, Nicol & Conway, 1994; de Villiers, Cahillane & Altreuter, 2006) show almost perfect usage. The aim of this study is to verify this asymmetry between pronoun production and pronoun comprehension for Dutch, and to investigate the effects of coherent discourse and topicality on pronoun production and comprehension. Employing a truth-value judgment task and an elicited production task, this study indeed finds such an asymmetry in 83 Dutch children (age range 4 ; 5–6 ; 6). When object pronouns were clearly established as the topic of the target sentence, the Pronoun Interpretation Problem dissolved entirely. These results are compatible with the asymmetrical grammar hypothesis of Hendriks & Spenader (2005/2006) and suggest, contrary to many previous claims, that children are highly proficient at using pragmatic clues in interpretation.

This study analysed the naturalistic productions of because and so by 96 children, vaged 3; 6–9; 6, vwhile vnarrating real, vpersonal events. Few semantic errors could be construed as evidence of confused thinking; none is a confusion vdescribed by Piaget. Of the vsemantically correct causal uses, 81 % encode psychological causality, mostly statements of other people's intentions. Other analyses revealed: (1) many of the relationships encoded are highly predictable, (2) virtually all causality occurred prior to the time of narration, (3) age trends are remarkably absent, (4) because and so are used in significantly different ways even by the youngest children, (5) only eight sentences showed a vreversal of the appropriate order of cause and effect. The discrepancy between the last finding and many other laboratory studies vwhich find many such reversals may be due to the fact that children are causally linking strictly successive events only 32 % of the time; for the rest, they are encoding events that partially or completely overlap in time.

Six children were visited in their homes every two weeks for 18 months from the age of six months in order to observe their developing comprehension and production of words. Controlled testing of the children's developing vocabulary was also carried out to provide a more detailed picture of the precise context in which a word was understood or produced. The results showed both similarities and individual differences among the children in patterns of early comprehension. For all six children there was a very close relationship between early production and comprehension of words: words that were contextually flexible in production tended also to be so in comprehension and words that were context-bound also tended to be so in both modalities although there was some evidence that the two types of word differed in the extent to which comprehension preceded production. All children were also similar in showing evidence of contextually flexible comprehension very early on. However, there were individual differences both in the rate at which comprehension developed and in the lag between comprehension and production. The significance of this pattern of development for accounts of lexical development is explored.

Existing studies have observed a robust relationship between infants' pointing gestures and language outcomes. By contrast, infants' overall vocal production is not related to language outcomes. One possible explanation for the association between pointing and language is that pointing gestures, as compared to vocalizations, may elicit more verbal responses from social partners that are facilitative for language learning. To test this, we observed forty-seven infants aged 1;0 during free play with their mothers and fathers separately to compare parents' verbal responses to infants' pointing gestures and object-directed vocalizations. Results showed that, compared to object-directed vocalizations, infants' pointing elicited more verbal responses from parents, particularly object labels. Moreover, mothers were more likely than fathers to provide labels. These results may help explain why pointing is associated with indices of language acquisition, but the production of vocalizations is not.