The study examined the transition to purposive use of intonation with single words for two children. Contrary to Bloom's (1973) claim of no systematic use of intonation in the one-word period, purposive use of rising tones was demonstrated in the context of indicating interest and naming objects. One child, by 1;3, clearly used rising tones to ask ‘legitimate’ questions in which the content of the replies mattered. If an informative response was not given he repeated his question accentuating the rising tone. The other child also sought informative replies, although this could only be established at 1;6. In addition, by 1;5 both children demonstrated widespread grammatical use of intonation in which a word was combined with distinct intonations to indicate a meaning distinction equivalent to one made by the grammar of the language. There were, however, earlier developments that presaged the way, so that the transition to grammatical use of intonation was gradual.

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.

The first 50 words of three blind children were collected and analysed using procedures used by Nelson (1973) on 18 sighted children. The early vocabulary of the blind children paralleled that of the sighted children in the age and speed of acquisition, and in the underlying characteristics of what the children chose to label. These reflect a sensorimotor organization in which self-action and perceptual change are the salient variables. The early words of the blind children differed from those of sighted children in the percentage of words in each of Nelson's grammatical categories. This suggests differences in how the children use language. These differences are discussed as a function of the children's lack of vision and their particular language learning context.

Phonetic and phonological analyses were performed on spontaneous speech samples of six 2–year–old monolingual Puerto Rican Spanish-learning children. The analyses showed a number of patterns of sound usage similar to those found in English-learning children of the same age, as well as children from other linguistic backgrounds. These findings add support to the claim that certain universal patterns exist in phonological development. However, a number of patterns were also observed which seemed to be accounted for by the target language being acquired. Similarities and differences among the individual children are also discussed.

The current study documented one child's earliest use of prepositions during her second year of life. The spatial oppositions up-down, on-off, in—out and over—under were first to be learned. These words were all used initially in non-prepositional senses (mostly as holophrastic, verb-like requests for activities) prior to prepositional usage. They were seldom omitted or misused. The prepositions with, by, to, for, at and of were learned later. Four of these were used to express at least two distinct case relationships, and some case relationships (instrumental and dative) were indicated by more than one of these words. These later learned prepositions were not used by adults or learned by the child as holophrases, but rather they were acquired as distinct lexical items by means of analytic learning strategies that employed some form of ‘extraction’ from adult phrases. These words were omitted and misused much more often than the spatial oppositions. Differences in the acquisition pattern of these two groups of prepositions were attributed to linguistic rather than to cognitive factors.

This study investigated the use of stative, process, punctual, and non-punctual verbs by a child acquiring Japanese as a first language between the ages of 1;0 and 4;11 in an attempt to find evidence for two of Bickerton's (1981) proposed language acquisition universals, which form part of the language bioprogram hypothesis of language acquisition. As predicted by Bickerton's state-process hypothesis, it was found that all sampled present progressive verb forms occurred with process verbs while these forms were never used with stative verbs. Also, with only one exception, all omissions of present progressive forms occurred with the early use of ‘mixed’ verbs, i.e. verbs which behave syntactically as process verbs in Japanese but are nonetheless semantically stative. However, contrasting with Bickerton's hypothesis that children initially use the past tense to mark punctuality, no relationship between past tense use and punctuality was found.

Children's reported copying-without-deletion errors, like ‘Whose is that is?’, have often been interpreted as the result of a non-adult rule of subject–aux inversion. By contrast, this study presents a performance account of these errors and supports this account by investigating what factors impede children's performance. Using an elicitation task, 16 test sentences were evoked from 16 3- to 5-year-old children. In particular, errors appeared (1) when the subject NP contained a relative clause, (2) when the relative clause had an object gap, and (3) when the relative clause was long. Since errors occurred in response to some sentence types and not others, and the children who made copying-without-deletion errors produced at least four correct responses, these results were interpreted as support for the performance account.

When asked to write an utterance, nursery children and kindergartners often produce strings of unrelated characters. We analysed whether these invented writings reflect similarities and differences in the phonetic and semantic aspects of the utterance. One hundred and twenty Israeli children were asked to write pairs of nouns that share a syllable (e.g. pe ‘mouth’ and perach ‘flower’) and series of sentences that share either mainly nouns or mainly verbs. The older the children, the more their invented writing reflected common linguistic elements and length of utterance. Similarities and differences on the word level were represented at a younger age than those on the syllabic level. Nouns were represented in children's written productions earlier than verbs and adverbs. Invented writing was interpreted as a linguistic act, drawing on the semantic, syntactic and phonological levels of language.

Four studies are reported in which young children's response time to detect word targets was measured. Children under about six years of age did not show the response time advantage for accented target words which adult listeners show. When semantic focus of the target word was manipulated independently of accent, children of about five years of age showed an adult-like response time advantage for focussed targets, but children younger than five did not. It is argued that the processing advantage for accented words reflects the semantic role of accent as an expression of sentence focus. Processing advantages for accented words depend on the prior development of representations of sentence semantic structure, including the concept of focus. The previous literature on the development of prosodic competence shows an apparent anomaly in that young children's productive skills appear to outstrip their receptive skills; however, this anomaly disappears if very young children's prosody is assumed to be produced without an underlying representation of the relationship between prosody and semantics.