This paper presents a detailed analysis of early lexical and phonological development in three children. The study covers the period from late babbling through the acquisition of 50 conventional words and focuses on: (1) the relationship between prelinguistic and linguistic vocalizations; (2) phonological development after the onset of speech; (3) patterns of lexical selection; (4) rate of lexical acquisition; and (5) use of invented words. The findings reveal that while the prelinguistic utterances of the children were similar, there was extensive inter-subject variation after the onset of meaningful speech, particularly in the segmental and syllabic forms of word productions, patterns of lexical selection, rate of lexical acquisition, and use of invented words.

Samples of babbling productions of 6-, 8- and 10-month-old infants from different language backgrounds were presented to adult judges whose task was to identify the infants from their own linguistic community. The results show that certain language-specific metaphonological cues render this identification possible when the samples exhibit long and coherent intonation patterns. The segmental indications that are present in the fully syllabic productions of canonical babbling do not allow the judges to identify the infants correctly from their own linguistic community. These results seem to support the hypothesis of an early influence on babbling of the metaphonological characteristics of the target language.

The hypothesis that there is a close relationship between object permanence and early language acquisition has not been supported by most previous research. McCune-Nicolich (1981), however, performed a detailed theoretical analysis and, as a result, found a close relationship between stage 6 object permanence development and the use of relational words. Unlike previous studies which used mostly quantitative measures of language, McCune-Nicolich related object permanence to the semantic content of the child's early words. She concluded that relational words enter the child's lexicon ‘as a group’ during stage 6, due in part to the development of the cognitive abilities of that stage. The current study attempts to make this claim more specific and consequently more accurate. Relational words requiring the conceptualization of the visible displacement of objects should emerge during stage 5, those involving invisible displacements during stage 6, and those referring to more complex spatial displacements only later during the pre-operational period. Data from a longitudinal study of six 1-year-olds corroborate this more specific account.

Four Italian infants' cry and non-cry vocalizations were recorded during laboratory sessions and grouped into different categories in relation to different situational contexts. Narrow-band spectrograms were taken of all infants' vocalizations in order to determine their non-segmental features. The results give evidence of differentiation of cry vocalization produced in different contexts, and similarity of cry and non-cry vocalization produced in the same context. The problem of assigning communicative intentions to prelinguistic children is discussed in a Piagetian perspective, assuming that infant vocalizations are schemes of interactions with the social world, developing in a similar way to sensorimotor schemes of action.

Recent studies suggest a specific relationship between the acquisition of the word ‘gone’ and the development of the object concept. A longitudinal study investigated whether there is a similar relationship between the acquisition of words that encode success and failure, such as no, uh-oh and there, and the development of means–ends skills. A cross-sectional study investigated both these relationships. The results suggest that children acquire the word gone after they solve simple invisible displacement tasks but before they solve serial invisible displacement tasks. They also show that children acquire success/failure words after they use insight to solve the problem of the string but before they use insight to solve more difficult means–ends problems. These sequences cannot be explained in terms of age, general cognitive development or general linguistic development. It is argued that gone encodes a concept related to the concepts that underlie success on invisible displacement tasks, and that success/failure words encode concepts related to the concepts that underlie the development of insight. Children seem to acquire words that encode concepts they have just developed or are in the process of developing. These results suggest that there are strong and specific links between the acquisition of particular types of meanings and particular cognitive achievements. Several alternative explanations for these early links between semantic and conceptual development are proposed.

The relationship between the acquisition of gone and the development of the object concept is investigated. Children acquire gone at the same time that they solve serial invisible displacement tasks, in a transitional period in the development of the object concept. According to a ‘neo-piagetian’ account of the object concept, children move from using specific rules to predict the reappearance of objects, to using a general theory of object movements during this period. The children's uses of gone suggest that gone encodes the fact that the child does not perceive an existing object. This concept is an essential component of the new theory of objects developed in this period. Children seem to acquire gone when they are in the midst of developing the concept that gone encodes, which may explain why they acquire the word in this period. In this case, conceptual development does not precede semantic development; rather, conceptual and semantic development appear to proceed simultaneously.

Children's responses to verbal instructions to place objects in, on, or under other objects were examined according to the paradigm developed by Clark (1973). In the present study, however, all objects were unfamiliar to the children, and were completely neutral and context-free. An additional task assessed children's comprehension of the spatial terms by asking them simply to point to objects in particular relationships without actually manipulating them. The results supported Clark's hypothesis of the influence of non-linguistic strategies on younger children's responses, in contradistinction to other studies critical of Clark's findings. However, when not required to manipulate the objects, children indicated greater comprehension than otherwise expected. The results are discussed in relation to the influence of task context on comprehension studies of this type.

Although higher pitch has been described as a universal feature of babytalk (BT) registers worldwide, analysis of a sample of three Quiche Mayan-speaking mothers addressing their infant children indicated that their BT register does not utilize this feature. Quiche mothers either make no pitch distinction in speech to young children, or actually lower pitch slightly in comparison with their Adult–Adult interaction style. A comparison group of American mothers raised pitch 35–70 Hz when addressing infants of the same age and language maturity. We posit that pitch-raising strategies may be sociolinguistically determined and may serve different functions across languages.

This study explores the question of whether maternal gestures facilitate aspects of the linguistic or communicative behaviour of young children. Four children aged 1; 4 were videotaped playing with their mothers in an unconstrained free condition, and then again in an ungestured condition in which mothers were instructed not to use their hands while interacting with their children. Results from the two conditions of our study show that though children tended to produce attentive responses when they had observed a gesture, these reponses were not necessarily more appropriate to the interaction than responses not preceded by maternal gesture. We conclude that maternal gestures have more of a role in maintaining attention and the flow of interaction for young children than they do in providing specific cues to the grammar the child is acquiring.

Partially conflicting results from correlational studies of maternal speech style and its effects on child language learning motivate a comparative discussion of Newport, Gleitman & Gleitman (1977) and Furrow, Nelson & Benedict (1979), and a reanalysis of the original Newport et al. data. In the current analysis the data are from two groups of children equated for age, in response to the methodological questions raised by Furrow et al.; but, in line with the original Newport et al. analysis, linguistic differences between these age-equated children are handled by partial correlation. Under this new analysis the original results reported by Newport et al. are reproduced. In addition, however, most effects of the mother on the child's language growth are found to be restricted to a very young age group. Moreover, the new analysis suggests that increased complexity of maternal speech is positively correlated with child language growth in this age range. The findings are discussed in terms of a theoretical analysis of the Motherese Hypothesis; the conditions of both learner and environment in which ‘simplified’ data could aid a learner. Finally, the results of our past work, those of Furrow et al., and those of the present analysis, are discussed as they fit into, and add to, current theorizing about the language acquisition process.

Previous studies have reported systematic individual differences among children in their noun and pronoun use. This study examined mothers' use of nouns and pronouns and their references to objects and persons as environmental variables which might relate to children's nominal preferences. Mothers' speech to children classified as referential or expressive in speech style (Nelson 1973) at low and high MLU levels (Nelson 1975) was analysed, and differences relating to children's style and MLU were reported. Results showed no relationship between mothers' use of nouns or pronouns and children's speech style, but did show that mothers' references to objects and persons were related to children's style. These findings are the strongest evidence to date that environmental factors contribute to stylistic differences in language acquisition, and also give support to Nelson's (1973) hypothesis that the communicative functions of language are an important factor in referential and expressive speech styles.

The production of voice-onset time (VOT) was studied in a group of Spanish- and English-learning subjects at 1 and 2 years of age. Voice-onset time of initial stop consonants from canonical utterances was measured oscillographically. At one year no significant difference in VOT production was found between Spanish and English learners at any place of articulation. Mean VOT values for infants fell in the short lag range. By two years, four of the seven children in the English group and four of the children in the Spanish group showed significant evidence of having acquired the VOT distinction in stop consonants appropriate for their native language.

A cross-sectional and a longitudinal study of 2-year-old children was performed to investigate the developmental relationship between understanding differences in spatial point of view and correct comprehension and production of I/you pronouns. In Study I only those children who demonstrated understanding that individuals' points of view can differ had begun to master speaker's point of view, as shown by correct use of some of the pronouns. Only children with complete understanding of points of view were able to use all I/you pronouns without errors. In Study 11 no child used the set of I/you pronouns without errors until s/he had complete understanding of points of view. Across children, a given pronoun tended not to be free of errors until the child understood that points of view can differ. Results are interpreted to support the hypothesis that understanding spatial points of view is a cognitive prerequisite to understanding speaker's point of view, which governs the pragmatics of 11 you pronouns.

This study experimentally investigated the hypothesis that some of young children's overextensions are analogic expressions by comparing children's labelling of objects in a naming task to their labelling of the same objects in a play situation. All of the 11 children (1; 8–2; 4) renamed substitute objects during pretend play. Criteria were established which identified 27% of children's renamings as analogic. Analysis of children's choice of substitute objects in pretend play showed that older children's (2; 2–2; 4) selections were influenced by their previous naming of the objects. In addition, both younger and older children tended to choose more functionally similar objects over more physically similar objects although ambiguous objects were renamed most often. Records collected by mothers for one week provided further evidence that children spontaneously produce analogic extensions.

Brown & Hanlon (1970) reported that parents' explicit approval or disapproval of their child's utterances was not contingent on the well-formedness of that utterance. Rather, parents seemed attuned to the semantic value of their child's speech. Using 40 mother–child dyads, 10 from each of four age groups, 2–5 years, we replicated these results. We expanded upon this earlier work, however, to suggest that parents are not totally indifferent to the grammatical form of their child's utterances. Focusing on repetitions, we found that mothers are more inclined to repeat ungrammatical than grammatical sentences generated by 2- year-old subjects. This indicates that the language learning environment does present subtle cues that distinguish between well-formed and ill-formed sentences. Whether the child is capable of capitalizing on these cues remains unanswered.

Patterns of vowel articulation in conversational speech to an adult and to child listeners were analysed in the speech of nine mothers. Formant frequency analysis of vowels embedded in 2,406 words found in varying syntactic environments and uttered by women to pre-verbal, holophrastic and more advanced child listeners (MLUs 2·5–4·0) revealed an emerging pattern of content word clarification, as measured by wider dispersion and decreased overlap between vowel phoneme categories in formant characteristics. Additionally, function word clarification was noted in speech to the oldest children. Vowel production appears to be modulated by child–addressee language ability. Earlier studies suggesting a lack of phonetic clarification in mother–child speech may have investigated speech to children too mature to elicit maternal clarification behaviours.

Longitudinal and cross-sectional designs were combined in this analysis of the evolution of children's capacity to represent deictic relationships. The longitudinal component contained the naturalistic observation of three relatively young children (1; 7–1; 9) and three somewhat older children (2; 0–2; 2). These children were tape-recorded in caretaker–child interactions. The analysis of the corpora from these children revealed: (1) imperfective activity verb phrases in the past tense, (2) telic verb phrases in the past tense used independently of resulting states, (3) moderately remote past references, and (4) deictic future references. The cross-sectional component contained an experiment in which elicitation procedures were used to obtain past and future references to atelic and telic situations. Nine 2½- and nine 3½-year-old children were tested. Generally high levels of performance reinforced the outcome of the longitudinal analysis.

To examine the effects of direct intervention on language learning, 18 children ranging in age from 3;6 to 4;6 were systematically taught linguistic structures still beyond their developmental grasp. Four types of relative clause sentences were trained, using a toy manipulation task. Solid improvement was found in the performance of subjects in the two experimental conditions between the Pre- and Post-test Phases. No significant improvement was demonstrated by the control condition subjects. This successful outcome is viewed as demonstrating that the language learning process is somewhat independent of cognitive development. In addition, error response analyses indicated that the First Noun strategy accounted for the majority of errors, providing support for the canonical–sentoid hypothesis.

Previous studies on the acquisition of causative verbs have analysed the deviations noticed in children's speech as resulting from the child's overgeneralized hypothesis about the morphological configuration of causative verbs. These studies are based on one type of deviation – the use of a non-causative verb for a causative verb. In this paper, longitudinal data are presented on the development of the lexical expression of causativity by one child learning Portuguese as her first language. Not only are non-causatives used for causatives, but causatives are also used for non-causatives. The latter type of deviation provides evidence for an analysis according to which the child takes into account the syntactic structure where causative verbs occur.

This study attempts to determine whether subject–auxiliary inversion occurs in yes–no questions before wh-questions and whether non-inversion errors (when daddy will come home?) are a characteristic feature of the acquisition of wh-questions. The data consist of the yes–no and wh-questions of 18 children, aged 2;5 to 3;0 with an mlu range of 2.66–4.26. Findings do not support previous claims that inversion is acquired in yes–no questions before wh-questions. Rather, a significant number of children were found to use an optional inversion rule in both question types. This fact appears to account for the finding that non-inversion errors are a characteristic feature of the acquisition of wh-questions.