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.

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.

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.

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.

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.

A repertoire of polysyllabic words, produced by an approximately 2-year-old child, was analysed for primary stress application. A general rule for stress application did not emerge from the data. Instead, much variability existed among tokens of individual lexical items (which were imitative and/or spontaneous) and among different lexical items with the same stress contour, regarding the placement of primary stress. Intraword and interword variation suggested the existence of four groups of words treated differently with respect to primary stress placement. The word groups were separated by their characteristic stress contours, which were (1) conventional primary stress, (2) misplaced stress, (3) level stress, and (4) undetermined stress. In general, consistent application of conventional stress was related, significantly, with lexical items represented by primarily spontaneous tokens. Results support a view of lexical primacy during early stages of learning word stress.

The acquisition of to in infinitive complement structure was examined in the spontaneous speech data from four children, who were observed longitudinally from two to three years of age. The children learned to as a complementizer connective in the context of a small group of verbs and other matrix forms that take a verb phrase complement. They did not learn to in the context of the complement verbs to mark the infinitive. Secondly, the children learned to with the meaning ‘direction towards’ and not as a meaningless syntactic marker. These results contribute to understanding the relation between the acquisition of complex syntax and the verb system in child language, and to evaluating traditional and contemporary linguistic theories of infinitive complement structure in English.

Studies of locatives suggest regularities in order and age of acquisition, including systematic changes in context of use for behind and in front of. The present investigation extends earlier work by utilizing more naturalistic elicitation procedures and exploring an early use of behind and in front of with large reference objects. Thirty-three children, ages 2; 7 to 4; 7, told puppets where to look for missing objects. Results indicate an order of acquisition for English locatives which is consistent with prior reports. However, the puppet story method elicited given locatives at younger ages, and the first uses of behind occurred with large, non-featured reference objects. The patterns of use for behind and in front of suggest an acquisition process in which new conceptual resources lead to the re-analysis of object configurations and thus to new aspects of meaning.

Natural language samples of 114 children aged 6 to 12 years are analysed for instances of discourse connectivity via adverbial conjuncts and disjuncts. Conjunct use is just emerging at 6 and is limited to the encoding of a subset of possible logical relations with only one lexical item per relation (transitional now, inferential then, result so and concessive though). Developmental progress takes the form of increasing use of the same conjuncts, plus additional logical relations and an increasing repertoire of lexical items per relation. Disjunct use is rare at all ages and largely limited to really and probably. Developmental interactions between form, content and use (discourse context) are probed. The 12-year-old child falls far short of an adult rate of production but is learning a similar set of connectivity forms.