The purpose of this study was to determine (1) whether mothers simplify their speech during the second half of the first year of development when infants begin to comprehend words and use gestures to communicate intentionally, and (2) whether individual differences in mothers' speech adjustments influence their infants' later language acquisition. The subjects for the study were 14 mother-infant pairs from a medically low risk sample who were followed longitudinally. Mothers' mean length of utterance (MLU) was calculated from transcripts of face-to-face interaction when the infants were 0;3, 0;6, and 0;9 in age. Mothers who provided responsive and stimulating environments, as indicated by HOME scores, also reduced their MLU over the age range studied. Moreover, mothers' MLU adjustments during the first year were more predictive than the HOME scale in forecasting receptive language development at 1; 6. In contrast, expressive language abilities at 1; 6 were unrelated to the environmental variables measured but were predicted by child characteristics such as the infant's sex. These results suggest that a mother's ability to ‘fine-tune’ her early linguistic input may be predictive of her child's later receptive language functioning. Precursors of fine-tuning, such as maternal beliefs in reciprocity and infant object orientation, are discussed.

In order to isolate the properties of language whose development can withstand wide variations in learning conditions, we have observed children who have not had access to any conventional linguistic input but who have otherwise experienced normal social environments. The children we study are deaf with hearing losses so severe that they cannot naturally acquire spoken language, and whose hearing parents have chosen not to expose them to a sign language. In previous work, we demonstrated that, despite their lack of conventional linguistic input, the children developed spontaneous gesture systems which were structured at the level of the sentence, with regularities identifiable across gestures in a sentence, akin to syntactic structure. The present study was undertaken to determine whether one of these deaf children's gesture systems was structured at a second level, the level of the gesture – that is, were there regularities within a gesture, akin to morphologic structure?

We have found that (1) the deaf child's gestures could be characterized by a paradigm of handshape and motion combinations which formed a matrix for virtually all of his spontaneous gestures, and (2) the deaf child's gesture system was considerably more complex than the model provided by his hearing mother. These data emphasize the child's contribution to structural regularity at the intra-word level, and suggest that such structure is a resilient property of language.

Data are derived from videotapes made in the homes of six Down's syndrome children with developmental ages varying between 1;1 and 2;1. The analysis concerns those sequences in which parent and child look at a book together, and more specifically those exchanges where the child initiates communication on a new target on the page. The design of these initiations is examined with respect to their various verbal and non-verbal components. The analysis of pointing, and in particular of point duration, reveals a possible developmental progression from a stage at which point and exchange duration are linked together to one in which the organization of pointing becomes more detached from the exchange as a unit of interaction.

This paper re-opens the question of whether imitation plays a significant role in the acquisition of grammar. Data for this study came from four samples of naturalistic mother-child speech taken over the course of one year from four autistic, four Down's syndrome and four normal children, covering a range of MLU stages. In general, autistic children used more formulaic language, including imitations, than Down's syndrome children, who in turn used more than the normal children. Comparisons of imitative and spontaneous corpora from the same transcripts were made using MLU and the Index of Productive Syntax. The main findings were that, with few exceptions, spontaneous speech utterances were longer, and contained more advanced grammatical constructions than did the imitation utterances. These findings held across all three groups of subjects. We conclude that imitation does not facilitate grammatical development.

Adult recasts of child utterances have been shown to be related in a general way to the child's acquisition of syntactic structures. The current study had two aims. The first aim was to determine which feature(s) of recasts (i.e. reformulation, expansion, topic continuation, or reply) was responsible for facilitating language acquisition by comparing them to other maternal discourse models that were systematically defined by these properties. The second aim was to investigate this relation more specifically by relating adult discourse models of specific grammatical morphemes to the child's acquisition of those same morphemes. Again, recasts were of particular interest. Twelve mother-child dyads were videorecorded during one hour of naturalistic interaction when the children were 1;10 and 2;4. Results indicated that maternal recasts of specific morphemes were related to the acquisition of those same grammatical morphemes during certain developmental periods, whereas other grammatical morphemes were facilitated by expansions and topic continuations. These results are discussed in terms of the processes responsible for these effects.

This study examines the relationship between cross-sectional measures of referential style taken at 1;1 and measures based on the first 50 words in 12 first-born children. Since no significant relationship is found it is argued that age-defined cross-sectional measures are inappropriate for the study of strategy differences in early language development because they confound such differences with variation due to differences in development level.

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.

This is an exploratory case study of the relation between speech output disturbances (dysfluencies) and the development of language production processes. The data consist of transcribed weekly speech samples of a Dutch boy between 2;4 and 2;11. The period of observation captures the early phase of the transition from ‘pre-grammatical’ to grammatical language. The frequency of occurrence of dysfluencies (i.e. repetitions, revisions and incomplete phrases) shows a significant increase and a subsequent decline. Whereas in the first half of the observation period the dysfluencies are distributed relatively randomly over sentences, in the second half they tend to concentrate in function words and sentence-initial words. The decline of dysfluency rate is shown to be related to an abundant use of a few ‘syntactic frames’. It is argued that these results reflect the emergence of a component in the speech production apparatus which is specifically dedicated to serial-order planning.

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.

Giving good definitions requires controlling both word meaning and definitional form. Definitions from 137 second to fifth graders (i.e. aged seven to eleven) were scored to reflect conformity to the classic Aristotelian form and quality of information provided. Comparisons among children with different backgrounds indicated that school exposure to English was strongly related to per cent formal definitions given and their quality. 63 children were also tested in French, their foreign language. Performance in French was lower than in English; exposure to French at home related to the amount of information the children provided in informal definitions, not to quality of formal definitions. The results suggest that performance on definitions is most strongly affected by opportunities to practise the required form.

The input language addressed to 18 language-learning children (MLU 1.00–3.00) was analysed so as to assess the quality of the semanticsyntactic correspondence posited by the semantic bootstrapping hypothesis. The correspondence appears to be quite satisfactory with little variation from the lower to the higher MLUs. All the persons and things referred to in the corpora were labelled by the mothers using nouns. All the actions referred to were labelled using verbs. Most of the attributive information was conveyed by adjectives. Spatial information was expressed through the use of spatial prepositions. As to the functional categories, all agents of actions and causes of events were encoded as subjects of sentences. All patients, themes, sources, goals, locations, and instruments were encoded as objects of sentences (either direct or oblique). This good semantic-syntactic correspondence may make the child's construction of grammatical categories easier.