The possibility that infant vocalizations occur in conjunction with significant changes in experience was tested in a study of seven infants aged 0;8. Each infant was videotaped during an isolated freeplay session with each of three toys. Two indices of changing experience were used to identify portions of the tape where increased vocalizing was expected. The Place Index identified potentially significant changes in experience via major changes in locus of attention. The Reaction Index employed certain rapid changes in expression (e.g. smile, startle, browchange as indicators of corresponding changes in subjective experience. As predicted, periods of the tape encompassed by either or both of these indices evidenced significantly more vocalizations than remaining portions of the tape. Implications of these results for theories of infant communicative competence and for infant language development are discussed.

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.

The purpose of the present study was to determine whether the VERBAL component of babytalk affected the vocal quality of infants. Two groups of 20 0;3 infants experienced either conversational turn taking or random responsiveness of an adult. Adult responsiveness consisted of a smile, light touch to the abdomen, and a NONVERBAL ‘tsk, tsk, tsk’ sound (instead of speech). All infant vocalizations were counted and then coded as ‘syllabic’ or ‘vocalic’ sounds. The results of the study demonstrated that TURN TAKING facilitated a speak-listen pattern of vocalizing by the infant, but in the absence of the VERBAL component of the adult's response, turn taking had no special facilitative effect on syllabic sounds. It was concluded that what adults say to 3-month-old infants influences what infants ‘say’ in return. Possible mechanisms underlying the infant's vocal response to verbal input were reviewed. It was suggested that the more mature sounds (syllabic) may proportionally increase as a result of the combined effects of turn-taking and verbal stimulation on the motor control of respiration and phonation.

This work describes the importance of the transcription process in studies of speech and language acquisition. Using data collected from a hearing child of deaf parents, the three authors derived independent transcriptions of the same speech sample and systematically compared their transcripts with each other and with the best estimate of the speaker's actual productions. The resultant transcripts were used to produce two descriptions of this child's phonological system, one based on a liberal estimate and one on a conservative estimate of the potential error in the transcripts. Discussion includes suggestions for deriving percentages of inter-transcriber agreement and the utility of such figures as a metric of transcription difficulty as well as transcriber ability.

Maternal speech to 3-month-old infants was compared for American and Japanese mother-infant dyads. Utterances were analysed at the levels of function, form and referent, and in relation to infant gaze direction. Loglinear categorical analysis revealed that infant gaze affected the intended functions of maternal speech differently for the two cultural groups. Cultural differences were also seen in the nature of function-form, and function-referent relationships. The differences seem to be consistent with culture-characteristic profiles of maternal behaviour towards older infants and children. It is suggested that transmission of culture through maternal speech starts at the earliest stage of infant development.

Previous studies have suggested that paternal vocabulary selection in speech to young children may be more diverse or demanding than that of mothers. This study examined the speech of eight mothers and eight fathers to their young language learning children. Nominal usage was subjected to TTR and frequency-of-occurrence analyses. In general, while paternal speech does not appear to be more diverse than maternal speech, it does appear to be characterized by greater usage of rare vocabulary and significantly lower usage of common vocabulary than is maternal speech.

Most processes in child phonology have as their domain a single word or a smaller chunk of phonological material. Processes that involve the interaction of two or more words have never been examined. In a diary study of the speech of one child acquiring English, there were eight between-word processes. All were optional and occurred in fairly restricted environments. Most of the processes were of short duration. Consequences for the study of child phonology are discussed.

Young children's initial categories often are not identical to the adult category labelled by the same word. Eventually, children's categories must evolve to correspond to the adult standard. The purpose of this study was to consider the relative effectiveness of four input strategies in inducing the child to learn the adult-appropriate label and begin to form a new category. Fifty-six children aged 2;0 were taught new labels for objects that they included in categories labelled by different names. Comprehension and production post-tests were then administered. As expected, the most effective strategy involved labelling an object and providing both a physical demonstration and a verbal description of important attributes that made the object a member of the adult-appropriate category. The label plus physical demonstration strategy was next most effective. Neither the label plus verbal description strategy nor the label only strategy was effective for children of this age. Results also indicated that these 24 month olds did not yet honour the convention of mutual exclusivity of basic level categories.

Three factors have been hypothesized to play an important role in the reduction of children's initial overextensions: spontaneous adult use of the correct label, correction of the child's errors, and demonstration of the important attributes that make an object a member of its adult category. The role of these factors was examined in relation to data collected from a longitudinal study of early lexical development. This study used an observational methodology combined with systematic comprehension and production testing. Results indicated that demonstrations were the most important factor in inducing toddlers to assign an object to its adult category. The question of why purely linguistic input initially plays a minor role in changing children's categories is discussed.

This article uses longitudinal data from four Mexican-American children to explore two aspects of the acquisition of Spanish word stress that precede and accompany learning of the stress system itself. First, contrary to Allen & Hawkins' proposed universal ‘trochaic bias’ (Allen 1982, Allen & Hawkins 1977, 1979, 1980), it is shown that children have a ‘neutral start’ in stress learning: they approach the task of stress learning unbiased towards any particular stress type. Secondly, several examples are found in which children's attention to phonetic or semantic aspects of normatively unstressed syllables leads them to shift stress to that syllable.

The current study assessed the child's learning of an object label in two conditions: when its referent was highly similar and when its referent was highly dissimilar to the referent of a known child word. Twenty-two 2-year-old children were taught the name for an object. In a session several days subsequent, they were taught names for two new objects: one which was highly similar and one which was highly dissimilar to the referent of the word learned in the first session (two stimulus sets assured counterbalancing). In this second session, children produced the word with the similar referent more often than the word with the dissimilar referent. In third and fourth sessions (several days later), children continued to show better performance with the similar word in comprehension. These results were interpreted as evidence that young children find it easier to learn a new word when they are able to contrast its referent with that of a word they already know.

Two studies of children's early language comprehension were performed using the signal detection paradigm introduced by Thomas et al. (1981). Experiment 1 replicated the original findings of Thomas et al., demonstrating that 13-month-olds understand a word that a parent reported they would understand and did not understand a word that a parent reported they would not. In Experiment 2, the procedure was modified to test for overextensions in early language comprehension. On half of the trials, children saw an array of objects including a referent for a ‘known word’. On the other half, the array included an object perceptually similar to the referent of the known word, but which itself was not an appropriate referent (e.g. an apple instead of an orange). Though the children demonstrated an understanding of the known word, they also overextended that word to the inappropriate referent. Mechanisms for such overextensions are discussed, as is the general relationship between comprehension and production.

Four mother–child dyads were videotaped in a longitudinal study of the relationship between linguistic input to children and early lexical development. Diary records were also kept by the mothers and, together with the videorecordings, were used to identify the contexts in which the children produced their first words. These were compared with the contexts in which the mothers used these same words. It was found that there was a strong relationship between the children's initial use of words and the most frequently occurring use of these words by the mothers. It was also found that although the majority of the children's first words were context-bound, a significant number were referential. The implications of these findings for current theoretical proposals concerning early lexical development are discussed.

This paper explores children's early talk about specific distant past events and its development into conversational stories of personal experience, with special focus on its evaluative function. The data consist of longitudinal home observations of five working-class children and their mothers from ages 2; 0 to 2; 6. Results indicate that during this period the children talked primarily about negative past events, especially events of physical harm; the rate of talk about specific past events doubled; temporally-ordered sequences increased dramatically; and the children became better able to accomplish such talk independently. In addition, one of the most striking findings is the extent to which these 2–year-olds were able to communicate their attitude toward the past event, with speech about the past containing five times more evaluative devices than other speech. These results suggest that (1) by age 2; 6 stories of personal experience emerged in incipient form, and (2) the roots of this genre lie not only in cognitive skills and social interactional support but in the emotional significance of the depicted event.

Negative utterances were collected longitudinally from two English-, five French- and four Korean-speaking children between 1;7 and 3;4. An analysis focusing on both non-verbal context and linguistic form led to the distinction of nine semantic/pragmatic categories which could capture cognitive and linguistic development in some detail: non-existence, prohibition, rejection, failure, denial, inability, epis-temic negation, normative and inferential negation. The nine categories were found in all three languages and their developmental order was similar across the languages. Different patterns were shown concerning the form-function relationship for different categories; for some categories, the distinct form emerged gradually after the function was acquired, while for others, the distinct form emerged simultaneously with the new function. Thus new forms emerged to subdivide an old category or to express a new function. This pattern was most typical for categories developed at later periods. It is suggested that whereas cognitive development precedes language development at an early period, at later periods cognitive and language development interact with each other.

A modelling experiment was conducted to determine if children would benefit from observing speech not addressed to them in discovering the correct use of first and second pronouns. Imitative behaviours of 18 English-speaking children who were about to learn personal pronouns were analysed under two modelling conditions. The non-addressee condition provided the child with systematic opportunities to observe the parents saying me/you with pointing actions directed towards each other as well as the parents saying me/you with pointing action directed towards the child. The addressee condition provided the child only with systematic opportunities to observe the parents saying me/you with pointing actions directed towards the child. Only children in the non-addressee condition imitated their parents' pointing actions and use of me/you without errors, suggesting that even children under two years old can attend to and can learn from speech not addressed to them.

The development of the forms and functions of interrogatives in parent-child interaction in the early stages of language acquisition is discussed with illustrative examples from data relating to two Tamil-speaking children and their parents. The analysis of the data reveals that children first acquire and use intonation questions followed by enga ‘where’, enna ‘what’ and yaari ‘who’. Yes/no questions using the interrogative marker -aa are acquired in the next stage when the children are able to use verb endings. Similarly question words that take case markers are acquired in the next stage. It is emphasized that interrogatives serve a multiplicity of communicative functions and are not restricted to the information-seeking role. Children, when they begin to use interrogatives, model their usage of them on the adult behaviour patterns to which they have been exposed, both in terms of form and function.

The Principle of Contrast, that different words have different meanings, holds for adult language use. But at what age do children assume Contrast ? Do they rely on it from the start, or do they assume that new words may have the same meaning (the Null Hypothesis) until they discover otherwise ? Both the Null Hypothesis and Contrast have certain consequences. The Null Hypothesis places a heavy burden on languagelearners, whereas children could discover Contrast as part of their experience of rational behaviour. Examples that have been claimed to go counter to Contrast fall into two groups. Those in the first do not in fact violate Contrast at all. Those in the second rely on sameness of extension instead of sameness of meaning, and so are indeterminate as counter evidence. Usage consistent with Contrast, on the other hand, is pervasive in children's speech from an early age.

Recent linguistic studies have proposed that verb morphology has evolved to serve particular functions inherent to discourse. In this paper, an attempt is made to apply this proposal to the development of verb morphology in the spontaneous speech of a child from 1;10. 16 to 2;0.2. The question asked was whether there were any aspects of the child's discourse which may have been in part responsible for her differential use of verb morphology. To answer this question, a distributional analysis is presented of the child's speech in two different speech contexts: dialogue vs. crib-monologue. Despite the exiguous amount of data in the corpus, the analysis yields striking patterns of co-occurrences involving verb morphology and forms of self-reference. The patterns were interpreted as provisional evidence that the child may have been sensitive to discourse factors in her selective use of verb morphology. The data is analysed into four developmental phases. It is suggested that the semantic-level meanings of Phase IV are due in part to the type of discourse use to which the morphology is put in the earlier phases.

The count/mass distinction represents a categorical differentiation of nouns into count nouns which can be individuated when quantified (e.g. a car, several tables) and mass nouns which may not (cf. *a water, *several sands). The emergence of this distinction was examined in the longitudinal speech data of two children. In the first analysis, use of count nouns and mass nouns was compared in noun phrase contexts that require count nouns (e.g. a X, another X). It was found that from the earliest samples children used more count nouns in these contexts, hence showing a distributional distinction of noun types. This result suggests very rapid acquisition of count/mass subcategories. A series of further analyses assessed the possibility that early differentiation of count and mass nouns may be due to rote learning. No evidence was found for this proposal. A final analysis examined the development of a rule that requires that singular count nouns must be modified by a determiner. Acquisition here was found to be more protracted in nature since determiners are not used consistently in ‘telegraphic’ speech. Problems concerning the learnability of the obligatory determiner rule are discussed along with some speculations concerning the role of semantics in the acquisition of the count/mass distinction.