One problem of interest in child language study has been specifying what features of the speech situation determine what children will say. Several cognitively based approaches to child language development have proposed principles of ‘informativeness’ to explain the child's choice of word(s). These principles predict that the child will choose the ‘most informative’ element of a situation and encode it in speech. Detailed inspection of this view reveals that the notion of ‘informativeness’ is not rigorously denned as in information theory, and would require the development of formal semantic and pragmatic information theories. Simpler accounts of available data do not require the notion of ‘information’.

Two suprasegmental characteristics of three children's single-word, successive single-word and multiple-word utterances were examined spectrographically. The location of terminal pitch contour and the duration of words were compared across the three utterance types. It was found that successive single-word utterances shared suprasegmental patterns, on these dimensions, with multiple-word forms but not with single words. It is argued that successive single-word utterances are not simply single words uttered in close temporal proximity. Further, an account of the underlying organization of successive utterances is proposed.

This study investigated the relationships between children's linguistic environments and their language acquisition. Speech samples taken from seven firstborn children and their mothers when the children were 1; 6 and 2; 3 were analysed within a number of semantic and syntactic categories to determine correlations between mothers' speech and subsequent language development. Several characteristics of mothers' speech (e.g. utterance length, use of pronouns) significantly predicted later child speech. The significant correlations suggested that mothers' choice of simple constructions facilitated language growth. Further, they showed that the motherese code differed from adult-adult speech in ways which aided language development. Differences between our study and previous investigations of environmental effects on language development probably resulted from the failure of earlier investigations to take into account children's level of language competence at the time when environmental effects were assessed.

This study investigates the surface forms which mothers use to direct their children's behaviour. It is generally supposed that social factors control a speaker's choice of directive form. However, it is shown that mothers' use of the various forms may be related to a cognitive variable, viz. the degree to which the forms possess the surface properties and, hence, clarity of canonical imperatives. As children get older, mothers' directives lose, in a meaningful order, properties which help to specify their mood and content. It is suggested that the social properties of the context do eventually replace the cognitive demands of the various forms as the primary influence on mother's choices.

Twelve nursery school children (mean age = 3; 9) attempted to imitate sentences which varied systematically in rate of presentation, intonation and length. The children more successfully imitated shorter sentences than longer ones, and sentences spoken at a rate nearer their own than sentences spoken at slower or faster rates. The imitation of long sentences read with normal intonation was superior to the imitation of long sentences read with flat intonation. Since adults frequently address children in short sentences, spoken slowly and with exaggerated intonation, these results indicate that these speech modifications may enhance the children's language comprehension.

Criteria were devised to distinguish between literal and metaphoric word usage in early language. These criteria were applied to the spontaneous speech transcripts of one child between 2; 3 and 4; 10.15. All unconventional word uses were identified and were then scored as overextensions, anomalies, or metaphors. The majority of unconventional word uses proved to be metaphors. Moreover, a developmental sequence of types of metaphors produced was found: those metaphors predominant during year 2 were based on the pretend actions of symbolic play; those predominant at year 4 were based on perceptual grounds alone, without the support of action.

It is argued in this paper that 4-year-old children do not perform logical operations corresponding to formal logic upon the sentential components of implicative verbs to produce the indirect implications, as was suggested by Macnamara, Baker & Olson (1976). First, it is shown that the indirect implications tested by Macnamara et al. are not the implications which would be derived on the basis of formal reasoning. Second, additional empirical evidence is presented to show that when children hear a story containing a sentence with an implicative verb they do not combine the sentential components of that implicative verb (i.e. the presuppositions and implicative) to arrive at the implication of their conjunction. It is argued that the children draw upon their past personal knowledge concerning the event described in the story and import additional premises where necessary in order to derive the indirect implications.

Ten objects were used to assess comprehension, production, and imitation of comparative and superlative suffixes in 100 children ranging in age from 2; 6 to 4; 6. The results indicated that comprehension of both suffix forms was similar at each of five age levels studied; although incrementally better comprehension scores occurred with succeeding ages. Virtually all subjects were successful in imitating forms missed during the comprehension task. Analysis revealed that the -er suffix was produced more often than the -est suffix, at the youngest age (2; 6): at succeeding age levels this difference was reversed. Big was the primary lexical unit selected by the subjects for positive and negative polar forms connoting size; little was the second most frequently used adjective form.

The ability of children between the ages of 2; 0 and 4; 8 to produce locative pre- or postpositions was investigated in English, Italian, Serbo-Croatian, and Turkish. Across languages, there was a general order of development: (1) ‘in’, ‘on’, ‘under’, and ‘beside’, (2) ‘between’, ‘back’ and ‘front’ with featured objects, (3) ‘back’ and ‘front’ with non-featured objects. This order of development is discussed in terms of nonlinguistic growth in conceptual ability. Language-specific differences in the general pattern of development are discussed in terms of a number of linguistic factors which may facilitate or retard the child's discovery of the linguistic means for encoding concepts.

The use of locative prepositions by Hebrew-speaking children aged 2; 0–3; 0, was investigated in a cross-sectional study. Thirty kibbutz children served as subjects. The spontaneous utterances of each child were analyzed and scored for the frequency with which the child supplied obligatory contexts for locative expressions as well as for appropriate use. The findings suggest the following order of acquisition: be- ‘in’; le- ‘to’; le+ pronominal suffixes ‘to’ (dative); al ‘on’; le ‘to’ (directional); mi- ‘from’; al-yad ‘beside’; meaxorey ‘behind’; mitaxat le- ‘under’. The role of formal linguistic complexity in determining that order is discussed. Special reference is made to the contrast between enclitic prefix prepositions and separate word prepositions that express the same locative notions.

The data obtained in two investigations (one a longitudinal/cross-sectional naturalistic study, the other a quasi-experimental study) demonstrate that preschool age children have the capacity for hypothetical reference. However, the data also indicate that this capacity for hypothetical reference operates within certain constraints, particularly early in the preschool years. Specifically, future hypothetical reference is an earlier acquisition than past hypothetical reference; reference to single hypothetical events appears sometime prior to reference to sequences of hypothetical events; and accuracy is better in self-initiated than other-initiated hypothetical reference. The implications of these findings are discussed.