A speech act approach to the transition from pre-linguistic to linguistic communication is adopted in order to consider language in relation to behaviour generally and to allow for an emphasis on the USE of language rather than on its form. The structure of language is seen as non-arbitrary in that it reflects both attention structures (via predication) and action structures (via the fundamental case grammatical form of language). Linguistic concepts are first realized in action. A pilot study focusing on the regulation of JOINT attention and JOINT activity within the context of mutuality between mother and infant is discussed, with emphasis on ritualization in mutual play as a vehicle for understanding the development of the formal structures of language.

This study compares the prosodie modifications in mothers' and fathers' speech to preverbal infants in French, Italian, German, Japanese, British English, and American English. At every stage of data collection and analysis, standardized procedures were used to enhance the comparability across data sets that is essential for valid cross-language comparison of the prosodie features of parental speech. In each of the six language groups, five mothers and five fathers were recorded in semi-structured home observations while speaking to their infant aged 0; 10–1;2 and to an adult. Speech samples were instrumentally analysed to measure seven prosodic parameters: mean fundamental frequency (f0), f0-minimum, f0-maximum, f0-range, f0-variability, utterance duration, and pause duration. Results showed cross-language consistency in the patterns of prosodic modification used in parental speech to infants. Across languages, both mothers and fathers used higher mean-f0, f0-minimum, and f0-maximum, greater f0-variability, shorter utterances, and longer pauses in infant-directed speech than in adult-directed speech. Mothers, but not fathers, used a wider f0-range in speech to infants. American English parents showed the most extreme prosodic modifications, differing from the other language groups in the extent of intonational exaggeration in Speech to infants. These results reveal common patterns in caretaker's use of intonation across languages, which may function developmentally to regulate infant arousal and attention, to communicate affect, and to facilitate speech perception and language comprehension. In addition to providing evidence for possibly universal prosodic features of speech to infants, these results suggest that language-specific variations are also important, and that the findings of the numerous studies of early language input based on American English are not necessarily generalisable to other cultures.

This study sought to determine why American parents from different socioeconomic backgrounds communicate in different ways with their children. Forty-seven parent–child dyads were videotaped engaging in naturalistic interactions in the home for ninety minutes at child age 2 ; 6. Transcripts of these interactions provided measures of child-directed speech. Children's vocabulary comprehension skills were measured using the Peabody Picture Vocabulary Test at 2 ; 6 and one year later at 3 ; 6. Results indicate that: (1) child-directed speech with toddlers aged 2 ; 6 predicts child vocabulary skill one year later, controlling for earlier toddler vocabulary skill; (2) child-directed speech relates to socioeconomic status as measured by income and education; and (3) the relation between socioeconomic status and child-directed speech is mediated by parental knowledge of child development. Potential mechanisms through which parental knowledge influences communicative behavior are discussed.

The study of language acquisition underwent a major revolution in the late 1950s as a result of the dissemination of technology permitting high-quality tape-recording of children in the family setting. This new technology led to major breakthroughs in the quality of both data and theory. The field is now at the threshold of a possible second major breakthrough stimulated by the dissemination of personal computing. Researchers are now able to transcribe tape-recorded data into computer files. With this new medium it is easy to conduct global searches for word combinations across collections of files. It is also possible to enter new codings of the basic text line. Because of the speed and accuracy with which computer files can be copied, it is now much easier to share data between researchers. To foster this sharing of computerized data, a group of child language researchers has established the Child Language Data Exchange System (CHILDES). This article details the formation of the CHILDES, the governance of the system, the nature of the database, the shape of the coding conventions, and the types of computer programs being developed.

Lists of the first 50 words comprehended and produced by eight infants between 0; 9 and 1; 8 were compared. Comprehension development began earlier (around 0; 9) and reached the 50-word level (age 1; 1) earlier than production development (ages 1; 0 and 1; 6 respectively) and rate of word acquisition for comprehension was twice that of production, confirming the hypothesis that comprehension precedes production for lexical development. Word-class analysis revealed differences in the proportion and type of action words in comprehension and production vocabularies. It is suggested that action is central to lexical development but is expressed differently in comprehension, where action words are used to initiate actions, and production, where non-action words accompany the child's actions.

A new method to assess language comprehension in infants and young children is introduced in three experiments which test separately for the comprehension of nouns, verbs, and word order. This method requires a minimum of motor movement, no speech production, and relies on the differential visual fixation of two simultaneously presented video events accompanied by a single linguistic stimulus. The linguistic stimulus matches only one of the video events. In all three experiments patterns of visual fixation favour the screen which matches the linguistic stimulus. This new method may provide insight into the child's emerging linguistic capabilities and help resolve longstanding controversies concerning language production versus language comprehension.

Several recent studies have demonstrated strong relationships between lexical acquisition and subsequent developments within the domain of morphosyntax. A connectionist model of the acquisition of a morphological System analogous to that of the English past tense (Plunkett & Marchman, 1993) suggests that growth in vocabulary size may relate to the onset of over-regularization errors. However, this model suggests that the relationships between vocabulary size and morphosyntactic development are non-linear. Incremental increases in the number of verbs to be learned result in qualitative shifts in the treatment of both previously learned and novel forms, but only after the size of the lexicon exceeds a particular level (i.e. reaches a ‘critical mass’). In this paper we present parental report data from an extensive study of English-speaking children aged 1;4 to 2;6 using the MacArthur Communicative Development Inventory: Toddler form (N = 1130). These data corroborate several findings from previous studies, including the early usage of unmarked verb stems and the correct production of irregular past tense forms. Further, we demonstrate support for the ‘critical mass’ view of the onset of over-regularization errors, focusing on continuity among lexical and morphological developments. In our view, these data suggest that these linguistic milestones may be paced by similar, if not identical mechanisms.

Results are reported for stylistic and developmental aspects of vocabulary composition for 1, 803 children and families who participated in the tri-city norming of a new parental report instrument, the MacArthur Communicative Development Inventories. We replicate previous studies with small samples showing extensive variation in use of common nouns between age o;8 and 1;4 (i.e. ‘referential style’), and in the proportion of vocabulary made up of closed-class words between 1;4 and 2;6 (i.e. ‘analytic’ vs. ‘holistic’ style). However, both style dimensions are confounded with developmental changes in the composition of the lexicon, including three ‘waves’ of reorganization: (1) an initial increase in percentage of common nouns from 0 to 100 words, followed by a proportional decrease; (2) a slow linear increase in verbs and other predicates, with the greatest gains taking place between 100 and 400 words; (3) no proportional development at all in the use of closed-class vocabulary between 0 and 400 words, followed by a sharp increase from 400 to 680 words. When developmental changes in noun use are controlled, referential-style measures do not show the association with developmental precocity reported in previous studies, although these scores are related to maternal education. By contrast, when developmental changes in grammatical function word use are controlled, high closed-class scores are associated with a slower rate of development. We suggest that younger children may have less perceptual acuity and/or shorter memory spans than older children with the same vocabulary size. As a result, the younger children may ignore unstressed function words until a later point in development while the older children tend to reproduce perceptual details that they do not yet understand. Longitudinal data show that early use of function words (under 400 words) is not related to grammatical levels after the 4OO-word point, confirming our ‘stylistic’ interpretation of early closed-class usage. We close with recommendations for the unconfounding of stylistic and developmental variance in research on individual differences in language development, and provide look-up tables that will permit other investigators to pull these aspects apart.

In a previous issue of this Journal, MacWhinney & Snow (1985) laid out the basic sketch for an international system for exchanging and analysing child language transcript data. This system – the Child Language Data Exchange System (CHILDES) – has developed three major tools for child language research: (1) the CHILDES database of transcripts, (2) the CHAT system for transcribing and coding data, and (3) the CLAN programs for analysing CHAT files. Here we sketch out the current shape of these three major tools and the organizational form of the CHILDES system. A forthcoming book (MacWhinney, in press) documents these tools in detail.

This research examines whether infants actively seek information from a speaker regarding the referent of the speaker's utterance. Forty-eight infants (in three age groups: 1;2–1;3, 1;4–1;5, and 1;6–1;7) heard novel labels for novel objects in two situations: follow-in labelling (the experimenter looked at and labelled the toy of the infant's focus) vs. discrepant labelling (the experimenter looked at and labelled a different toy than that of the infant's focus). Subsequently, half of the infants were asked comprehension questions (e.g. ‘Where's the peri?’). The other half were asked preference questions (e.g. ‘Where's the one you like?’), to ensure that their comprehension performance was not merely the result of preferential responding. The comprehension results revealed developmental change in both (a) infants' ability to establish new word-object mappings (infants aged 1;2–1;3 failed to establish stable word-object links even in follow-in labelling), and (b) infants' ability to pinpoint the correct referent during discrepant labelling (only infants aged 1;6–1;7 succeeded). Thus the period between 1;2 and 1;7 represents a time of change in infants' ability to establish new word-object mappings: infants are becoming increasingly adept at acquiring new labels under minimal learning conditions.

The transition from slow to rapid word-learning was examined in a longitudinal study of 18 children. Beginning at age 1;2, mothers kept a diary of children's words. Diary entries were discussed during phone calls to the home every 2½ weeks. A chronological record of nouns and other word classes was coded from the diary records.

Thirteen children evidenced a prolonged period of up to three months during which rate of acquisition markedly increased. Almost threequarters of the words learned during this period were nouns. Five children evidenced more gradual word-learning, and acquired a balance of nouns and other word classes. These results suggest that the terms ‘vocabulary spurt’ and ‘naming explosion’ best describe children who focus their early linguistic efforts on a single strategy: learning names for things. Other children may attempt to encode a broad range of experience with a more varied lexicon, a strategy that results in more gradual lexical growth.

Universally, object names make up the largest proportion of any word type found in children's early lexicons. Here we present and critically evaluate a set of six lexical principles (some previously proposed and some new) for making object label learning a manageable task. Overall, the principles have the effect of reducing the amount of information that language-learning children must consider for what a new word might mean. These principles are constructed by children in a two-tiered developmental sequence, as a function of their sensitivity to linguistic input, contextual information, and social-interactional cues. Thus, the process of lexical acquisition changes as a result of the particular principles a given child has at his or her disposal. For children who have only the principles of the first tier (REFERENCE, EXTENDIBILITY, and OBJECT SCOPE), word learning has a deliberate and laborious look. The principles of the second tier (CATEGORICAL SCOPE, NOVEL NAME – NAMELESS CATEGORY’ or N3C, and CONVENTIONALITY) enable the child to acquire many new labels rapidly. The present unified account is argued to have a number of advantages over treating such principles separately and non-developmentally. Further, the explicit recognition that the acquisition and operation of these principles is influenced by the child's interpretation of both linguistic and non-linguistic input is seen as an advance.

Analysing the gradual learning process through which a child becomes bilingual from early infancy, three stages can be distinguished: (1) the child has one lexical system which includes words from both languages; (2) the child distinguishes two different lexicons but applies the same syntactic rules to both languages; (3) the child has two linguistic codes, differentiated both in lexicon and in syntax, but each language is exclusively associated with the person using that language. Only at the end of this stage, when the tendency to categorize people in terms of their language decreases, can one say that a child is truly bilingual.

Parent report data on early language development measured using the MacArthur Communicative Development Inventory (CDI–Infant Form) was collected on 134 preschool children with autism spectrum disorder. The pattern of development of understanding of phrases, word comprehension and expression, and production of gestures, was compared to the typical pattern. In common with typical development there was considerable variability in language acquisition, although for the group as a whole this was significantly delayed compared to the normal course. In addition, atypical patterns were identified in the emergence of language skills in the sample. Comprehension of words was delayed in comparison to word production, and production of early gestures (involving sharing reference) was delayed relative to production of later gestures (involving use of objects). However, other aspects of language development were similar to that found in typically developing infants, including word comprehension being in advance of word production in absolute terms, gesture production acting as a ‘bridge’ between word comprehension and word production and the broad pattern of acquisition across word categories and word forms. The implications for assessment and intervention with preschool children with autism spectrum disorder are discussed.

When carefully assessed and analysed, parent report can provide a valuable overall evaluation of children's language at 20 months. Norming information and validity coefficients are presented here for a vocabulary checklist assessment included in the Early Language Inventory. Normative data are provided for fullterm, preterm, and precocious samples, including selected vocabulatory subsets that are indicative of early language learning style. The vocabulary checklist has substantial validity as indexed by correlations with the Bayley Scales of Infant Development and particularly with a language subscale derived from that test.

Our understanding of the relationships between lexical and phonological development has been enhanced in recent years by increased interest in this area from language scientists, psychologists and phonologists. This review article provides a summary of research, highlighting similarities and differences across studies. It is suggested that the research falls into two categories with different goals and different methodological approaches: (1) child-centered studies that examine the influences active in the prelinguistic and early-word period, emphasizing individual developmental patterns and the active role played by the child; and (2) studies inspired by research on word processing in adults; these focus on the effects of the phonological and lexical characteristics of the ambient language on underlying representations and word learning in children. The article concludes with suggestions for integrating the findings from the two approaches and for future research.

Twenty economically disadvantaged preschoolers (mean age 3;7) were randomly assigned to an intervention or a control group, and their mothers' styles of eliciting narratives from their children were assessed before and after intervention. Mothers of intervention children were encouraged to spend more time in narrative conversation, ask more open-ended and context-eliciting questions, and encourage longer narratives through back-channel responses. Children's narrative and vocabulary skills were assessed before and after the year-long intervention and 14 children participated in a follow-up assessment a year later. Narrative measures included the number and length of narratives as well as how decontextualized and informative they were. Intervention children showed significant vocabulary improvement immediately after intervention terminated, and a year later they showed overall improvements in narrative skill. In particular, intervention children produced more context-setting descriptions about where and especially when the described events took place. Such decontextualized language has been emphasized as important for literacy acquisition.

The arguments both for and against viewing the child's initial one-word utterances as HOLOPHRASES are reviewed. Some theoretical problems – concerning the innateness of language, the acquisition of syntax, the status of prosody and the child's comprehension of language during the one-word stage – with the holophrase controversy are pointed out. We suggest that an unresolvable theoretical stalemate exists because proponents on both sides of the controversy mistakenly assume the centrality of the notion sentence in discussing holophrases. An alternative view of early language development, which takes the SPEECH ACT as the basic unit of linguistic communication, is offered as a solution to the problems with the holophrase controversy as it now stands. We propose a more integrated description of the relations between functional and grammatical aspects of early communicative competence than is currently provided by sentence-oriented theories. In particular, we suggest that the child's PRAGMATIC INTENTIONS gradually become GRAMMATICALIZED as semantic and syntactic structures. Finally, three entities – communicative functions, referring expressions and predicating expressions – are proposed as LANGUAGE UNIVERSALS, as distinct from grammatical universals.

Divergent hypotheses exist concerning the types of knowledge underlying early bilingualism, with some portraying a troubled course marred by language delays and confusion, and others portraying one that is largely unremarkable. We studied the extraordinary case of bilingual acquisition across two modalities to examine these hypotheses. Three children acquiring Langues des Signes Québécoise and French, and three children acquiring French and English (ages at onset approximately 1;0, 2;6 and 3;6 per group) were videotaped regularly over one year while we empirically manipulated novel and familiar speakers of each child's two languages. The results revealed that both groups achieved their early linguistic milestones in each of their languages at the same time (and similarly to monolinguals), produced a substantial number of semantically corresponding words in each of their two languages from their very first words or signs (translation equivalents), and demonstrated sensitivity to the interlocutor's language by altering their language choices. Children did mix their languages to varying degrees, and some persisted in using a language that was not the primary language of the addressee, but the propensity to do both was directly related to their parents' mixing rates, in combination with their own developing language preference. The signing-speaking bilinguals did exploit the modality possibilities, and they did simultaneously mix their signs and speech, but in semantically principled and highly constrained ways. It is concluded that the capacity to differentiate between two languages is well in place prior to first words, and it is hypothesized that this capacity may result from biological mechanisms that permit the discovery of early phonological representations. Reasons why paradoxical views of bilingual acquisition have persisted are also offered.

This study explores the communicative use of the gestural and vocal modalities by normally developing Italian children during the transition from one- to two-word speech. We analysed the spontaneous production of 12 children at 1;4 and at 1;8, focusing on the use of two-element combinations of words and/or gestures. Results indicated that use of gesture and gesture-word combinations during the transition to two-word speech is a robust feature of communicative development across a relatively large number of children in a rich gestural culture, and that the number of gesture-word and two-word combinations increased significantly from 1;4 to 1;8. Number of gestures and gesture-word combinations produced at 1;4 was also predictive of total vocal production at 1;8. Findings are discussed in terms of the role of gesture as a transitional device en route to two-word speech.