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.

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.

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.

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.

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 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 explores how children learn the range of aspect inflections to which a verb is amenable. The data considered are from observations of three Japanese boys aged between 1; 10 and 2; 1. Analyses focus on the children's mastery of Aktionsart specific intersentential patterns. For example, in one pattern, a caregiver asks nani shiteiru? ‘What is someone or something doing’. The conventional answer is with the continuative -te iru form of a verb that expresses an activity. Three conclusions are drawn. First, lexical assignment had begun before aspectual inflections were used to signal temporal perspective switch. Secondly, lexical assignment began with anchorpoints tying certain lexical contrasts to the Aktionsart of minimal sentences. Thirdly, overgeneralizations of aspect inflections are due to the difficulty of acquiring devices that signal temporal perspective switch.

Whenever children hear a novel word, the context supplies information about its meaning. One way children may cope with so much information is to use whatever seems to make sense, given their prior knowledge and beliefs, while ignoring or quickly forgetting the rest. This work examined if and how children's beliefs about word meanings may affect their use of contrastive linguistic information in the input in word learning. In Study 1, some 3- and 4-year-olds were introduced to a novel material or shape name and heard it contrasted with familiar words. Others merely heard the novel word used for referring to an object. These children were then tested to determine what they had learned about their new word meaning. In Study 2, another group of 3-and 4-year-olds were asked to name the materials and shapes used for introducing these novel terms. Children made use of linguistic contrast only in some situations. They benefited more when the novel term did not overlap much in denotation with any terms commonly known by 3-and 4-year-olds. These results suggest that children can use information in the input very efficiently in learning a term for an as-yet-unnamed category, but not in learning a term similar in denotation to a word they already know. Thus, the results are consistent with the claim that children believe every word has a unique denotation.

In this paper, I review properties and consequences of the PRINCIPLE OF CONTRAST. This principle, which I have argued from the beginning has a pragmatic basis, captures facts about the inferences speakers and addressees make for both conventional and novel words. Along with a PRINCIPLE OF CONVENTIONALITY, it accounts for the pre-emption of novel words by well-established ones. And it holds just as much for morphology as it does for words and larger expressions. In short, Contrast has the major properties Gathercole (1989) proposed as characteristic of her alternative to Contrast.

To be well understood, narratives need to be embedded within appropriate contextual information. The early development of key orientation (participants, location and time) was traced with an 18-month longitudinal study of real-experience narratives produced by 10 children aged approximately 2–3; 6. Listener knowledge or inference was required to decode most named participants and many were not specified at all. There was no developmental improvement. Orientation to when was rare at first and involved formula words indiscriminately applied. There was steady developmental improvement in frequency as well as differentiation of time references. where information was more common at all ages, particularly when the narrated events occurred away from home. It also showed developmental improvement, but only for away-from-home locations. Overall, very young children can produce narratives in an unscaffolded context to adults unfamiliar with their experiences. The potential role of parental scaffolding in teaching orientation skills is discussed.

In a previous issue of this Journal, MacWhinney & Snow (1985) laid out the basic sketch for an international system for exchanging and analysing child language transcript data. This system – the Child Language Data Exchange System (CHILDES) – has developed three major tools for child language research: (1) the CHILDES database of transcripts, (2) the CHAT system for transcribing and coding data, and (3) the CLAN programs for analysing CHAT files. Here we sketch out the current shape of these three major tools and the organizational form of the CHILDES system. A forthcoming book (MacWhinney, in press) documents these tools in detail.

A description is given of the CHILDES/BIB database, its contents, and its relationship to the CHILDES database. CHILDES is a depository of child language corpora, and the publisher of CHAT (a transcription manual), and CLAN (an electronic package for child language research). CHILDES/BIB is an electronic bibliographic database that is an autonomous unit of CHILDES.

A younger group (mean age 5;10) and an older group (mean age 9;11) of children were asked to place a toy man IN FRONT OF or BEHIND a car which either faced away from them or faced sideways. When the observer's viewpoint was not emphasized in the instructions, or was merely implied, both age groups responded in a nondeictic way. When the viewpoint of the observer was an essential component of the task and the spatial term was omitted, both age groups selected a deictic location. However, when the viewpoint was emphasized but when the spatial term was also included the responses were split between deictic and nondeictic locations.