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.

The attribution of function of various kinds to elements of child speech is discussed, and the question of the validity of the interpretations on which such attribution rests is explored with reference to Halliday's work on the development of meaning. Work in the philosophy of language is used to explore the kind of evidence needed for valid interpretation, and its systematic nature within a framework of the structure of linguistic behaviour. It is argued that theoretical clarity in this area would aid the study of both language use and language acquisition.

The behaviour of 32 mothers during an object-retrieval game was analysed in terms of the hints and ‘clues’ they used to direct their children's attention. Age-related differences were found in the type of information offered; the prompts 2; 0-year-olds received primarily concerned the target-objects' whereabouts, whereas 2; 6-year-olds' mothers referred to the target-objects (especially those unfamiliar by name) in terms of the children's background knowledge of the objects' functions or associations, as well. Possible explanations for these changes are discussed and the view is advanced that these differences should be interpreted as reflecting changes in the way mothers structure the task for their children as they become more independent problem-solvers.

Judgements about the acceptability of anomalous and non-anomalous sentences were elicited from children between the ages of 2; 0 and 5; 0. Generally such judgements have been assumed to be a direct reflection of linguistic competence. Longitudinal study of individual children indicated that developmental changes in children's judgemental capacities were erratic, with sudden regressions in performance as well as sudden improvements. This was especially true of the youngest children, aged between 2; 0 and 3; 6. It appeared that, despite irregularity, certain general developmental patterns could be discerned. It is difficult to reconcile these findings with a view of sentence judgements which assumes that they directly represent linguistic competence. It is suggested that the most satisfactory explanation of the developmental data must rest on the assumption that not simply linguistic factors, but also cognitive/experiential factors are involved in sentence judgements.

This study challenges the semantic relations categories widely used for explaining children's early utterances. Ten 3-year-olds were asked two sets of questions involving the verb + with construction. Their responses were categorized according to existing semantic relations categories such as instrumental and locative. Problems with this approach emerged which were solved by developing a more simple dichotomous category system. The children responded by naming an item which is characteristically present for the duration of the given verb and not beyond its duration (chew with food). Thus the chosen item's presence was BOUNDED by the duration of the activity. When several items fitted the bounded criterion, the one most necessary for carrying out the activity was selected, and when no items fitted the bounded criterion, a non-bounded or continuously present item was reluctantly chosen.

Young children described objects which differed on three simultaneous dimensions, using adjective combinations appropriate to the dimensions. Three- and 6-year-olds displayed significant ordering preferences for these adjectives, which agreed with the ordering preferences of adults in the same task. Four- and 5-year-olds were less constrained in their adjective ordering, although descriptive competence with the adjectives improved greatly at age five. In a comprehension task, the children located the objects from verbal descriptions which used the same adjectives. Neither latency nor accuracy of comprehension was affected by the order of adjectives in the description at any age. The children also reproduced the adjectives in different orders; the few errors which occurred were unrelated to adjective order.

Comprehension of event order was compared for reversible ‘X because Y’ (‘Y because X’ is also logical) and non-reversible ‘X because Y’ sentences. Children aged 5; 8–10; 11 chose one of two picture sequences, differing in event order, and put two pictures in first/last order to match a sentence ‘X because Y’ (order of mention violates temporal order) or ‘Because Y, X’ (order of mention preserves temporal order). Reversibility and clause order effects reflected the use of semantic probability cues and order-of-mention strategies for comprehension. Judgements were also made of grammatical acceptability for correct and reversed ‘X because Y’ sentences. Response strategies used in the two experiments suggest that development of comprehension of the role of because reflects acquired independence from contextual support and acquisition of a meaning component: ORDER.

Developmental changes in verbal responses to systematic variations in linguistic contexts contrast with the data reported in the syntagmatic-paradigmatic shift studies. The present study indicates a protracted developmental shift extending from five years of age beyond nine years of age. Apparently the first priority is to create a linguistic context when none is given; once a linguistic context is realized, semantic-syntactic equivalences have priority, followed by differentiation and then integration.

This study was concerned with the question of how linguistic input of the social environment might affect children's acquisition of word meaning. It was argued that the conceptual impact of linguistic input could be demonstrated where the conceptual components underlying word meaning are not primarily based on perceptual categories, as in the case of kinship terms. In two experiments, 84 German children living in families, and 84 orphans, aged from 6 to 10, were compared in their ability to use natural or artificial kinship names as terms for kinship relations. The results suggested that a mere familiarity interpretation for the actual difference in the ability to use kinship terms could be ruled out. Orphans showed a specific conceptual deficit in handling relational components even when the familiarity of the terms was equated for the two groups. Two issues these results raise are whether the orphans' deficit will disappear with increasing age, and to what extent the correct use of kinship terms is due to differences in general intelligence.

Two branches of language functioning are now actively being studied: one focuses on language as a system for expressing syntactic-semantic relations, the other as a system of interpersonal communication. In this paper, a case is presented of a child who at 3; 3 showed a marked schism between these two areas. In the former domain he displayed behaviour that in most respects was age appropriate and relatively extensive. In the latter domain, he displayed almost totally ineffective functioning. His difficulties in the use of language for communication were mirrored from infancy by a serious failure either to understand or produce non-verbal communication (e.g. gestures). It is suggested that the structural and communicative aspects of language are based upon different sets of skills which particularly in cases of language disorder may function independently of one another.

Sentences were constructed in which the terms before and after were embedded in logically constrained and logically reversible sequences. As in French & Brown (1977), pre-school children found the constrained sentences easier to comprehend. These findings add a new dimension to Clark's (1971) original before and after study in which the effect of logically constrained sentences was not considered. The results of the two studies are consistent with a growing literature (including current formulations of semantic feature theory) which implicates contextual cues and child strategies in the comprehension process, and raises questions about the role of parental speech in the child's comprehension of temporal terms.