College students judged the relative ages of pairs of vocalizations sampled either from a Chinese infant at 0; 6, 1; 0 and 1; 6 or from an American infant at the same ages. The judgments were 88% accurate, with the easiest judgments contrasting the 0; 6 and 1; 6 samples (96% accurate). With one exception, age contrasts for the Chinese infant were as easy to judge as those for the American infant. However, a second sample of college students was unable to judge the linguistic community of the vocalizer when age was held constant, whether the data were drawn from infant samples of 0; 6, 1; 0 or 1; 6 or from adults babbling to babies. These data led to speculations on the kinds of cues speakers of different languages use to discriminate infant vocalizations, and whether these cues are age-specific or language-specific. The data presently suggest the former, but the present study has methodological limitations, and generalizations are limited to one specific language contrast, English and Chinese.

Conventional and displaced uses of pronouns in maternal speech to refer to the baby were investigated in a developmental study of six mother—infant dyads using video-recordings of their free play at three, seven and ten months. These pronominal uses were analysed in a number of semantic contexts to determine how interactive situations influence the use of different types of pronouns. Results show that third- and first-person pronouns occur significantly more often in the semantic context of affect-oriented activities than in the semantic context of goal-directed activities. For second-person pronouns the results are the opposite. The contrast found between these two contexts, i.e. where the child is presented as the agent of a meaningful activity or not, shows how the place constructed for the baby as an interlocutor in maternal speech evolves with age. This study underlines the part the third person plays with its descriptive value in the acquisition of the system of pronouns.

Recent work by Lust and others has led to the prediction that children acquiring left-branching languages will exhibit a preference for backward patterns of anaphora. In this paper, we test this prediction against data from Korean and Japanese and show it to be false. An alternative hypothesis proposing a preference for forward patterns of anaphora is outlined and possible explanations for earlier experimental results supporting Lust's prediction are considered.

Children as young as two years of age are able to learn novel object labels through overhearing, even when distracted by an attractive toy (Akhtar, 2005). The present studies varied the information provided about novel objects and examined which elements (i.e. novel versus neutral information and labels versus facts) toddlers chose to monitor, and what type of information they were more likely to learn. In Study 1, participants learned only the novel label and the novel fact containing a novel label. In Study 2, only girls learned the novel label. Neither girls nor boys learned the novel fact. In both studies, analyses of children's gaze patterns suggest that children who learned the new information strategically oriented to the third-party conversation.

An experimental elicitation task with children between the ages of 1;8 and 11;3 shows that children learning Thai numeral classifiers begin with purely distributional information: specifically, (1) that classifiers must appear in the post-numeral position, and (2) that classifiers comprise a conventional, closed set of words. Semantic organizing features, such as salient features of the head noun's referent, appear later than these syntagmatic organizing features. Use of such semantic information is not an immature ‘first guess’ at grammatical categories, but rather, a necessary component of adult linguistic competence, because the categories are productive both for older children and for adults.

The functions of acoustic-phonetic modifications in infant-directed speech (IDS) remain a question: do they specifically serve to facilitate language learning via enhanced phonemic contrasts (the hyperarticulation hypothesis) or primarily to improve communication via prosodic exaggeration (the prosodic hypothesis)? The study of lexical tones provides a unique opportunity to shed light on this, as lexical tones are phonemically contrastive, yet their primary cue, pitch, is also a prosodic cue. This study investigated Cantonese IDS and found increased intra-talker variation of lexical tones, which more likely posed a challenge to rather than facilitated phonetic learning. Although tonal space was expanded which could facilitate phonetic learning, its expansion was a function of overall intonational modifications. Similar findings were observed in speech to pets who should not benefit from larger phonemic distinction. We conclude that lexical-tone adjustments in IDS mainly serve to broadly enhance communication rather than specifically increase phonemic contrast for learners.

To code-switch or not to code-switch? This is a dilemma for many bilingual language teachers. In this study, the influence of teachers’ CS on bilingual children's language and cognitive development is explored within heritage language (HL) classes in Singapore. Specifically, the relationship between children's language output, vocabulary development, and cognitive flexibility to teachers’ classroom CS behavior, is examined within 20 preschool HL classrooms (10 Mandarin, 6 Malay, and 4 Tamil). Teachers’ and children's utterances were recorded, transcribed, and analyzed for CS frequency and type (i.e., inter-sentential, intra-sentential). 173 students were assessed with receptive vocabulary and dimensional card sort tasks, and their vocabulary and cognitive switching scores assessed using correlational and mixed effects analyses. Results show that inter-sentential and intra-sentential CS frequency is positively and significantly related to children's intra-sentential CS frequency. Overall, findings revealed that teachers code-switched habitually more often than for instructional purposes. Neither inter-sentential nor intra-sentential CS was significantly related to children's development in HL vocabulary, and intra-sentential CS was found to positively and significantly relate to children's growth in cognitive flexibility. These findings reveal the multi-faceted impact of teacher's CS on children's early development.

Pre-school children's comprehension of the adverbial modifiers very and sort of, when combined with two pairs of polar dimensional adjectives (big/little and tall/short) was experimentally investigated in 64 children (three, four and five years of age). The task involved the choice of an item from a graduated array of nine objects in response to questions combining the modifiers and adjectives. Results suggested that comprehension of very begins in the third year and is understood consistently by the four- and five-year-olds in combination with all four adjectives. Sort of is not understood by the three-year-olds, but appears to be available to the four- and five-year-olds. Results are interpreted as a reflection of an early appreciation that linguistic categories are not well bounded.

Previous studies have shown that by 11 but not by 10 months infants recognize words that have become familiar from everyday life independently of the experimental setting. This study explored the ability of 10-, 11-, and 12-month-old infants to recognize familiar words in sentential context, without experimental training. The headturn preference procedure was used to contrast passages containing words likely to be familiar to the infants with passages containing words unlikely to have been previously heard. Two stimulus words were inserted near the beginning and end of each of a set of simple sentence frames. The ability to recognize the familiar words within sentences emerged only at 12 months of age. The contrast between segmentation abilities as they emerge as a result of everyday exposure to language, as assessed here, and those abilities as measured in studies in which words are experimentally trained is discussed in terms of memory-based mechanisms.

Children's apparent ‘errors’ in interpreting ask as tell, incidentally uncovered in C. Chomsky's research on syntactic development, and subsequently interpreted in terms of E. Clark's theory of semantic development, are re-interpreted in the framework of pragmatic development. An experiment is reported in which a single coherent discourse framework is imposed and one pragmatic factor is manipulated: children's knowledge of the answers to the questions they are supposed to relay. The results confirm the hypothesis that if the children do not know the information, they relay the question, i.e. ask. If they do know the answer, they supply it, i.e. tell. By literally asking, the children in the ‘don't know’ condition demonstrate that they are capable of decoding ask constructions semantically and syntactically. The tendency of the children in the ‘know’ condition to tell is then interpreted as revealing not semantic confusion but pragmatic skill. The children's responses are discussed in relation to three-person speech acts and indirect requests for information. Children's ability to interpret utterances non-literally has implications for conducting experiments with literal instructions and these are also discussed.

This longitudinal study involving 101 Dutch four- and five-year-olds charts indirect request (IR) and mental state term (MST) understanding and investigates the role that Theory of Mind (ToM) and general linguistic ability (vocabulary, syntax, and spatial language) play in this development. The results showed basic understanding of IR and MST in four-year-olds, but full understanding had not been reached even at five years old. Furthermore, although ToM predicted both IR and MST when linguistic ability was not taken into account, this relationship was no longer significant once the language measures were added. Linguistic ability thus seems to play an important role in the development of both IR and MST. Additional analyses revealed that whereas syntactic ability was the primary predictor of IR, spatial language was the best predictor of MST, suggesting that IR relies primarily on general linguistic skills, but that more specific aspects of language may bootstrap MST.

The role of event knowledge in early language acquisition was investigated. Thirteen two-year-olds were observed interacting with their mothers over a five-week period. During weekly observational sessions, dyads interacted in both a familiar-event context and an unfamiliar-event context. Events were represented by complex toys (e.g. airport, marina, etc.). In the familiar-event, dyads interacted with the same event-toy during each observation period. In the unfamiliar-event, these same dyads interacted with a different novel toy during each observation period. The results indicated that children's increasing event knowledge facilitated their language development. Specifically, children's lexical type use, action verb use, and MLU increased in the familiar-event, but remained unchanged in the unfamiliar-event. Event knowledge also facilitated children's lexical token use. Results are discussed in terms of the role of event knowledge in language acquisition.

Data from one English-Italian bilingual child (1;10–3;1) are presented in this study which challenge the hypothesis that the consistent realization of overt subjects in English is caused by the emergence of finite verbal morphology in the child's grammar. The argument is made for the emergence of subjects as an independent grammatical property of English, namely the marking of person deixis. Throughout the period of observation there is a significant proportion of overt subjects in the child's English utterances appearing both with finite and non-finite verb forms. Production of subjects stabilizes at 90% of obligatory contexts when no morphological correlates of finiteness have been acquired yet. While subjects are produced at significantly lower rates in Italian, we observe the consolidation of a number of inflected forms marking person agreement. The emergence of overt subjects in English on the one hand, and of subject–verb agreement in Italian on the other suggest that this bilingual child is grammaticalizing the all-important function of person deixis in language-specific ways: the same function is expressed by different forms in the child's two languages.

This study describes how young Spanish-speaking children become gradually more adept at encoding temporality using grammar and discourse skills in intra-conversational narratives. The research involved parallel case studies of two Spanish-speaking children followed longitudinally from ages two to three. Type/token frequencies of verb tense, temporal/aspectual markers and narrative components were analyzed to explore interrelationships among grammatical and discourse skills. Children progressed from scattered unsystematic means of encoding temporality to mastering a basic linguistic system that included devices to mark location of events, temporal relations and aspectual meanings. The consolidation of perfective past tense to express narrative events marked a crucial developmental point which preceded an explosion of additional verb tenses and temporal markers. The value of spontaneous language data, and the need to study grammar and discourse simultaneously to construct a comprehensive developmental picture are highlighted. Results are discussed in relation to theoretical proposals on the development of temporality.

It has been proposed that cochlear implant users may develop robust categorical perception skills, but that they show limited precision in perception. This article explores if a parallel contrast is observable in production, and if, despite acquiring typical linguistic representations, their early words are inconsistent. The participants were eight Spanish-learning deaf children implanted before their second birthday. Two studies examined the transition from babbling to words, and the one-word period. Study 1 found that the participants used the same sound types in babbling and in words, indicating that production is guided by stored motor patterns. No clear evidence of inconsistent production was observed. Study 2 found that in the one-word period CI users develop typical prosodic representations, but that their productions are highly unstable. Results are discussed in terms of the role of auditory feedback for the development of productive language skills.

Purpose: Although school-age children learn most new word meanings from surrounding context, the joint roles of language ability and executive function (EF) in the word learning process remain unclear. This study examined children's acquisition of word meanings from context in relation to oral language ability and three EF skills (working memory, inhibitory control, and cognitive flexibility). Method: Typically developing school-age children completed measures of language and EF, then read and listened to short stories containing unfamiliar target words. A multiple-choice pretest–posttest measure assessed children's target word knowledge gains. Results: Regression analyses showed that language and cognitive flexibility were both related to word knowledge gains; each skill assumed greater importance among children with relative weakness in the other skill. Conclusion: Language ability and cognitive flexibility may each play a direct role in contextual word learning among school-age children, with children naturally relying on one skill if the other is weaker.

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.

Twenty-four caregivers and their two- to four-year-old children took part in a storybook reading task in which caregivers taught children novel labels (‘DAXY’) for familiar objects. One group (N=12) received labels modelled syntactically as proper names (‘This is NAMED DAXY’), and another group (N=12) received the same labels for the same objects modelled syntactically as adjectives (‘This is VERY DAXY’). Caregivers took strikingly different approaches to teaching words from the two lexical categories. In teaching proper names, but not adjectives, caregivers flagged cases in which one word was paired with two objects; two words were paired with one object; and one word was paired with an inanimate object. In teaching adjectives, but not proper names, caregivers discussed meaning and offered translations. Caregivers' distinctive strategies for teaching proper names and adjectives are congruent with recent findings about children's word meaning assumptions, and with analyses of the semantics of these lexical categories. The findings indicate that parental speech could provide a rich source of information to children in learning how different lexical categories are expressed in their native language.

Rules for interpreting empty category (EC) subjects of complement clauses vary crosslinguistically across structural and lexical dimensions. In adult Greek, a distinction is made between the verbs meaning WANT and TRY, the former but not the latter permitting the EC subject of its subjunctive complement to refer outside the sentence. The EC is pro for WANT and PRO for TRY. In adult Spanish, both the verbs meaning WANT and TRY require the EC subject (pro) to refer outside when the complement is in the subjunctive, and require the EC subject (PRO) to refer to the main clause subject when the complement is in the infinitive. Twenty-three Greek-speaking four- to five-year-olds and 10 adults, 29 Spanish-speaking four- to five-year-olds, 18 six- to seven-year-olds and eight adults took part in act-out experiments. The results indicate an awareness of language-particular distinctions governing the interpretation of EC complement subjects. However, child speakers of both languages experience difficulty in giving sentence external reference, leading to error in the case of subjunctive sentences for Spanish-speaking children. We argue that the data overall is most compatible with children having access to the empty category PRO by age four, and that failure to give external reference of an EC when required can plausibly be treated as performance error. A picture verification task produced less clear results, but points to the need for data from younger children to establish whether there is an early stage in which lexical semantics dominates children's interpretation of ECs.