This investigation examined phonetic variation in multisyllable babbling of infants from 0;7 to 0;11. The basis of this investigation was to examine assumptions present in major models of infant vocal development which suggest systematic developmental increases in phonetic variation of these babbles, and posit separate stages of repetitive (multisyllables with non-varied phonetic elements) and non-repetitive (phonetically varied multisyllables) babbling. Eight infants were audiotaperecorded in their homes at ages 0;7, 0;9 and 0;11. The multisyllable vocalizations were categorized based on the presence or absence of phonetic variation, and the source of that variation (place change, manner change or both). Multisyllables were produced with phonetic variation at or near the beginning of multisyllable babbling, which failed to support the existence of distinct stages of repetitive and nonrepetitive babbling.

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.

The role of babbling in language development is not well understood. One source of evidence is the utterances of infants who were tracheostomized during the period in which they would normally have produced syllabic vocalization. We describe here the phonetic patterns and linguistic development of a girl called Jenny. She was tracheostomized and generally aphonic from 0;5–1;8 but cognitively and socially normal, with near-normal comprehension of language. Acoustic analyses of Jenny's utterances following decannulation revealed a tenth of the canonical syllables which might be expected in normally developing infants, an extremely small inventory of consonant-like segments, and a marked preference for labial obstruents. In these ways, she resembled a group of infants of the same age who also cannot hear their oral-motor movements, the congenitally deaf, suggesting that the audibility of babbling contributes to its onset. Two months following decannulation, when Jenny was 1;10, she produced only a handful of different words. We think this is because aphonia prevented her from discovering the referential value of vocal expression and discouraged the formation of a phonetic repertoire that could be appropriated for lexical service. This unusual case suggests that babbling normally facilitates the development of language and speech.

This study examines the development of word order patterns in Irish, a strict VSO language. It was found that the three children studied used subject-initial utterances considerably more frequently than adults in input, and that in both adult and child the elision of the verb ‘to be’ played a significant role. Another significant factor was found to be the different restrictions on main verbs and verbal nouns with regard to the subject: in neutral sentences the main verb always precedes the subject, while the verbal noun always follows it. The Bates & MacWhinney (1979). hypothesis that early verb initialization results from a tendency to place new information before given information was also investigated.

In the literature on phonological acquisition certain strategies such as homonymy and reduplication are viewed as phenomena appearing at a very early age, resulting from a deficient sound-inventory and sound-distribution. Data on homonymy and reduplication from a longitudinal study will be considered, which show that: (a) such strategies can appear later in the child's linguistic development than it has been proposed; (b) the lexical item has to be considered a central unit, beyond the earliest stages, in the acquisition of phonology.

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.

Cognitive complexity and complexity of linguistic structure have been found to influence the order of acquisition of locatives. In Warlpiri, locative terms are nominals and they are used in combination with a locative case marker on the reference object; directional affixes may be added to them. Data from a series of tests of Warlpiri children's comprehension and production of the Warlpiri expressions that may be translated as ‘in’, ‘on’, ‘under’, ‘in front of’, ‘behind’ and ‘between’ indicate that the locative case forms are used first without the more specific locative nominals; young children distinguish an ‘up-down’ dimension but not ‘in’, and the reference object influences how the locative term is interpreted; kamparru-pirdangirli (‘front-behind’) is not one dimension for children aged four to five years; kulkurru ‘between’ is understood before kamparru ‘front’ and pirdangirli ‘behind’; the use of features on a reference object for orientation develops at around six, but the orientation of the reference object, as well as features on the placed object may affect interpretation.

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.

An American-Japanese comparison of maternal speech to 3-month-old infants is presented. Mother-infant dyads were videotaped in the laboratory, and the maternal speech was analysed by function and syntactic form. US mothers were more information-oriented than were Japanese mothers; they also used more question forms, especially yes/no questions. Japanese mothers were affect-oriented, and they used more nonsense, onomatopoeic sounds, baby talk, and babies' names. The differences between countries in maternal speech addressed to 3-month-olds appear to reflect characteristic culture-specific communicative styles as well as beliefs and values related to childrearing.

Counter to findings in English, German and Hebrew, recent acquisition studies have shown that the passive is acquired early in several non-Indo-European languages. In an attempt to explain this phenomenon, this paper addresses certain typological phenomena which influence the early acquisition of passives in Sesotho, a southern Bantu language. After outlining the structure of the Sesotho passive and its syntactic and discourse functions, I examine Sesotho-speaking children's spontaneous use of passives, showing that the acquisition of passives in Sesotho is closely linked to the fact that Sesotho subjects must be discourse topics. I conclude that a detailed examination of how passive constructions interact with other components of a given linguistic system is critical for developing a coherent and universally applicable theory of how passives are acquired.

In a longitudinal study concerned to assess Verb Phrase (VP) development in three Trinidadian children, adverbials were found to be crucial in delineating specific areas of semantic intent, and to develop early (between ages 2;3 and 3;0). The children were studied over a two-year period, from the onset of morphological marking on the verb, and were recorded two to four hours per month, in their home environments, with a variety of addressees. Two of the children were exposed to, and acquired, both TC and SE verb categories and the third, TC, but the existence of TC past-completive zero 0 as a prominent verbal marker in all their systems made for reliance on adverbial and extralinguistic context in delineating meaning intentions at an early stage;the use which they made of adverbial specification, in particular for marking perfect aspect, indicates how useful these elements may be for precise specification of the development of tense-aspect categories. When they are considered alongside other VP features a clearer overall assessment of tense–aspect development may be made.

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.

The present study compared four categories of maternal utterances that were found in a previous study (Hoff-Ginsberg, 1986) to predict children's rates of syntax development to a category of maternal utterances that was unrelated to syntax development. The comparisons were designed to test the hypotheses that maternal utterances which benefit syntax development do so by providing syntactically rich data or by eliciting conversation from the child. Data-providing and conversation-eliciting characteristics of the selected categories of maternal utterances were assessed from the same transcripts of 22 mothers interacting with their 2½-year-old children that had provided the database for the earlier study of predictive relations. Each of the three positive predictor categories of maternal utterances differed from the unrelated category — in more frequently illustrating the affected aspect of syntax development, in eliciting more speech from the child, or both. Neither of these characteristics was true of the negative predictor category. The pattern of results suggested that maternal speech supports the child's development of syntax by engaging the child in linguistic interaction and also by providing illustrations of the structures the child acquires.

We hypothesize that canonical sentence schemas (e.g. Agent—verb-Patient) can sometimes assign argument structure to verbs. In particular, they provide a default argument structure early in learning when a verb's lexical entry may record the nature of the action but lack a specific argument structure. To test the theory and its application to causative verb errors (e.g. stay it there), novel action verbs were modelled, some as causative, some as intransitive, and some unmarked for transitivity. Spontaneous usage was recorded, along with responses to agent-questions (‘What is the [Agent] doing?’) and patient-questions (‘What is the [Patient] doing?’). Comparable data were obtained for familiar English verbs, some of fixed and some of optional transitivity. Subjects were willing to use all novel verbs both transitively and intransitively, although adults respected assigned transitivity more than children. All subjects largely respected the transitivity of familiar verbs. The discourse pressure of the agent- and patient-questions greatly affected observed transitivity. No evidence was found for the intransitive-to-causative derivational process postulated by Bowerman. We propose that the kind of causativity error observed by Bowerman is due to assignment of argument structure from canonical sentence schemas, especially under pressure of a need to make a sentence with a particular argument (Agent or Patient) as subject. The theory has the advantage of explaining errors without postulating the acquisition of erroneous lexical entries that have to be unlearned, and it can be extended to other kinds of errors in the choice and placement of arguments.

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.

The aim of this study is to examine how caretakers speak to young children in a day-care centre and particularly to investigate how they adjust their language, according to children's age and to size of groups. Five Italian teachers were observed, each one during six different sessions. Children's ages were 0;10–1;2 and 2;6–3;0. The number of children varied from a rather large group (seven children) to a small group (three children) to a single child. Language was taperecorded during free-play sessions of ten minutes. Context was noted by two observers. Transcripts were analysed according to structural features (syntactical complexity, redundancy, type-token ratio, speed) and functional features (proportion of utterances with different purpose: control and organization of child behaviour, empathy, conversation and teaching). Results show some significant differences in structure and function according to children's age and group size.

This paper presents a study of young children's understanding of a constraint on English word order, which is that pronouns and proper names cannot be modified by prenominai adjectives. For adults, this is a syntactic constraint: adjectives can only precede nouns, and pronouns and proper names are lexical Noun Phrases (NPs). In two analyses, the spontaneous speech of 14 one- and two-year-old children was studied. These analyses show that even in children's very first word combinations, they almost never say things like big Fred or big he. Some non-syntactic theories of this phenomenon are discussed and found to have serious descriptive problems, supporting the claim that children understand knowledge of word order through rules that order abstract linguistic categories. A theory is proposed as to how children could use semantic information to draw the noun/NP distinction and to acquire this restriction on English word order.

Verb learning is clearly a function of observation of real-world contingencies; however, it is argued that such observational information is insufficient to account fully for vocabulary acquisition. This paper provides an experimental validation of Landau & Gleitman's (1985) syntactic bootstrapping procedure; namely, that children may use syntactic information to learn new verbs. Pairs of actions were presented simultaneously with a nonsense verb in one of two syntactic structures. The actions were subsequently separated, and the children (MA = 2;1) were asked to select which action was the referent for the verb. The children's choice of referent was found to be a function of the syntactic structure in which the verb had appeared.

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.