The purpose of these studies is to characterize children's conception of reversal and its relation to a reference state. A reversal is the move from one state to some prior state of affairs. For example, shoes that have been TIED can be UNTIED, parcels WRAPPED then UNWRAPPED, and dishes COVERED then UNCOVERED. The present studies were designed to find out how children (aged 1;0 to 5;0) describe reversals of action that restore objects to a prior, less constrained, state. In English, the prefix un- offers the most productive device for this, but, initially, children rely on a verb like open, on general purpose undo, and on particles like out and off, As they acquire un-, English-speaking children must learn that this prefix applies primarily to verbs for change-of-state, often for enclosing, covering and attaching. In German, there is no reversal prefix, but there are productive particles. German-speaking children also begin with a verb like open and then turn to verb particles on a course similar to that in English to express reversals.

The ability to convey the optimal amount of information during conversation is a fundamental aspect of language use. In this study the relationship between children's failures to produce unambiguous utterances and the mental effort demands of the communication task was investigated. Five-, six-, seven- and nine-year-old children performed a message production task and a finger-tapping task both separately and simultaneously. The decrease in finger-tapping frequency during the simultaneous performance was used as an estimate of effort demands of the message production task. Working memory capacity was assessed by means of a spatial memory test and an object features identification task. Children's intuitions about message adequacy were recorded in two message evaluation tasks. By age six children proved to be able to select the relevant information when they were explicitly asked to do so, indicating that effort demands of the communication task did not exceed their computational resources. However, results suggested that the relative effort requirements of the communication task decrease with increasing age. These findings support a performance theory of communication development in which effort demands are a determinant of children's message adequacy.

Lexical gaps in vocabulary development have been acknowledged as a reason for language mixing in young bilingual children. In spite of this, most studies do not take into account whether young bilinguals have the lexical resources to make a choice between their two languages. Inferences are nevertheless still being made about whether or not young bilinguals differentiate between their two languages based on language choice. It is widely believed, however, that young bilinguals do not have the resources to make lexical choices at a pre-syntactic stage of development before age two. A bilingual case study of an infant acquiring Spanish and English from birth to age 1;10 is used to address this issue. Daily diary records and weekly video recordings in the two language contexts are used to construct the child's lexicon and to establish that translation equivalents that make possible language choice are available from the beginning of speech. The results are used to discuss the importance of translation equivalents in the bilingual lexicon for viable interpretations of language choice.

In two investigations (N = 62 and 59), three- and four-year-old children sometimes disbelieved what they were told about the unexpected contents of a deceptive box, even when they had seen the adult speaker look inside the box before s/he told them what s/he saw, and despite being able to recall the utterance: utterances were treated as unreliable sources of knowledge compared with seeing directly. Those who did believe the utterance were no better at recalling their prior belief about the box's contents (now treated as false), than those who saw inside the box. However using a narrative procedure, we replicated Zaitchik's (1991) result that children are more likely to acknowledge another's belief when they are told about reality, than when they see reality for themselves. We argue that these children were acknowledging alternative rather than false belief.

Two studies are described which investigate preschool children's sensitivity to relative clauses as barriers to the movement of wh-questions. The children were presented with short stories followed by questions in which the wh-word had two possible sites of interpretation, the ungrammatical option being inside a relative clause. A cross-sectional study with 23 children aged 3;1 to 6;1, and a longitudinal study over the course of one year with 12 children aged 3;1 to 4;1 at the start, found young children refused to extract wh-questions from the ungrammatical site inside a relative clause. This confirms other findings that children's early grammars are sensitive to universal constraints on movement. In addition, the children differentiated between wh-complements and relative clauses in their tendency to mistakenly answer the medial wh-complementizer but not the wh-relative pronoun. Explanations for the latter are framed in terms of children's initial assumptions about the attachment of complements.

Two experiments examined the development of children's understanding of the difference between want and need. In experiment 1, children were tested on their knowledge that want represents an intrinsic desire whereas need represents an instrumental desire. Forty-five children between three and five years of age heard four stories in which one character encountered a problem, while another did not. A desirable object which could alleviate the problem was then introduced, and after both characters requested the object, the children were asked whether each character wants the object or needs it. Three-year-olds were unable to differentiate the two terms in such contexts, whereas four- and five-year-olds were significantly more likely to say that the character experiencing the problem needed the object, while the other wanted it. In experiment 2, 45 subjects between three and five years of age were tested on their understanding that a request employing need expresses a stronger desire than one employing want. Subjects were required to give an object to one of two characters, one of whom asked for it using need and the other using want. In this experiment, three-year-olds were equally likely to give the object to the character using want as to the one using need. Both four- and five–year–olds were significantly more likely to give the object to the character who used need. The results from these two experiments show that the understanding of the semantic and pragmatic difference between want and need develops at about four years of age.

This study examines the role of cognitive development in children's use of pragmatic cues for anaphora resolution. Reported speech sentences like Minnie told Dorothy that she knew Superman are biased toward the matrix subject. This bias is claimed to depend on two conceptual shifts, first to the speaker's and then to the listener's perspective. 141 children aged 5;0–8;0 performed two tasks with biased and neutral sentences. In the Verbal task, they gave antecedent choices in response to a question (e.g.… that WHO knew Superman?). In the Puppet task, which prompts the perspective shift, they made a puppet say the reported speech portion (e.g. I/you know Superman). Violations of the pragmatic constraint decreased with age and task, consistent with the perspective-shift model. Parallel function effects in neutral sentences were weaker than in previous research on conjoined sentences, but similar to recent results for adults with these materials.

Previous work bas demonstrated that children understand sentences with actional verbs better than nonactional verbs. This ACTIONALITY EFFECT bas been reportee to be restricted to passives and to be independent of experimental context. The present experiment was conducted with 48 French-speaking children aged 5;0–7;11. The actionality effect was studied by systematically varying the voice of the test sentences and the voice of the interpretive requests. Pictures corresponding or not to the predicate—argument structure of the sentences were presented to the subjects, who were independently classified as visualizers or nonvisualizers, in order to investigate the relation between sentence actionality and mental imagery. The interaction between actionality, voice of sentence, and interpretive request revealed that the actionality effect depends on the type of task used in order to assess comprehension, and that it can be reversed in some conditions. Our results also suggest that the actionality effect is linked to mental imagery. Visualizers demonstrated better comprehension of actional sentences than nonvisualizers, whereas the reverse was true for nonactional sentences. Mental image may serve as a support for the computations involved in sentence comprehension.

Experiments 1 and 2 examined the effects of infant-directed (ID) speech on adults' ability to learn an individual target word in sentences in an unfamiliar, non-Western language (Chinese). English-speaking adults heard pairs of sentences read by a female, native Chinese speaker in either ID or adult-directed (AD) speech. The pairs of sentences described slides of 10 common objects. The Chinese name for the object (the target word) was placed in an utterance-final position in experiment? (n= 61) and in a medial position in experiment 2 (n= 79). At test, each Chinese target word was presented in isolation in AD speech in a recognition task. Only subjects who heard ID speech with the target word in utterance-final position demonstrated learning of the target words. The results support assertions that ID speech, which tends to put target words in sentence-final position, may assist infants in segmenting and remembering portions of the linguistic stream. In experiment 3 (n= 23), subjects judged whether each of the ID and AD speech samples prepared for experiments ? and 2 were directed to an adult or to an infant. Judgements were above chance for two types of sentence: ID speech with the target word in the final position and AD speech with the target word in a medial position. In addition to indirectly confirming the results of experiments 1 and 2, these findings suggest that at least some of the prosodic features which comprise ID speech in Chinese and English must overlap.

The study investigated the effects of using props to illustrate the meaning of sentences in a syntactic awareness task in which subjects were required to correct ungrammatical sentences. Forty preschool children (aged 4;11 to 5;11) were asked to correct 20 sentences, 10 of which were illustrated using props, and 10 of which were not. Children scored significantly higher in the props condition though the proportion of meaning-changing errors to total errors was not significantly lower in this condition. It is argued that the use of props, by providing contextual support, reduces the processing capacity required to complete the task.

In past research, the form of Japanese children's personal narratives was found to be distinctly different from that of English-speaking children. Despite follow-up questions that encouraged them to talk about one personal narrative at length, Japanese children spoke succinctly about collections of experiences rather than elaborating on any one experience in particular (Minami & McCabe, 1991). Conversations between mothers and children in the two cultures were examined in order partly to account for the way in which cultural narrative style is transmitted to children. Comparison of mothers from the two cultures yielded the following salient contrasts: (1) In comparison to the North American mothers, the Japanese mothers requested proportionately less description from their children. (2) Both in terms of frequency and proportion, the Japanese mothers gave less evaluation and showed more verbal attention to children than did North American mothers. (3) Japanese mothers pay verbal attention more frequently to boys than to girls. In addition, at five years, Japanese children produce 1·22 utterances per turn on average, while North American children produce 2·00 utterances per turn, a significant difference. Thus, by frequently showing verbal attention to their children's narrative contributions, Japanese mothers not only support their children's talk about the past but also make sure that it begins to take the shape of narration valued in their culture. The production of short narratives in Japan is understood and valued differently from such production in North America.

Based on an analysis of similarity neighbourhoods of words in children's lexicons, Dollaghan (1994) argues that because of the degree of phonological overlap among lexical items in memory, children must perform detailed acoustic-phonetic analyses in order to recognize spoken words. This is in contradiction to Charles-Luce & Luce (1990), who reported that the similarity neighbourhoods in younger children's expressive lexicons are sparse relative to older children's and adult lexicons and that young children may be able to use more global word recognition strategies. The current investigation re-examined these issues. Similarity neighbourhoods of young children's RECEPTIVE vocabularies were analysed for three-phoneme, four-phoneme and five-phoneme words. The pattern of the original results from Charles-Luce & Luce (1990) was replicated.

The study examined whether the use of superordinate terms in children's definitions was predicted by relevance theory. Two hundred and six children aged five to ten years gave definitions for 16 basic-level words and four superordinate words from natural kind and artefact semantic domains. Superordinate terms were used more frequently when they supported more inferences. This was evidenced by their more frequent use in natural kind than in artefact domains, and more frequent use when the superordinate was itself defined by a semantically complex expression. When used, superordinates also usually occurred at the beginning of the definitional expression. It is argued that these findings reflect the speaker's intention to achieve optimal relevance, that is, to achieve maximum contextual effects with the least processing effort.

This paper brings a quantitative study of children's noun plural overregularizations (foots, mans) to bear on recent comparisons of connectionist and symbolic models of language. The speech of 10 English-speaking children (aged 1;3 to 5;2) from the CHILDES database (MacWhinney & Snow, 1985, 1990) were analysed. The rate of noun overregularization is low, mean = 8·5%, demonstrating that children prefer correct to overregularized forms. Rates of noun overregularization are not significantly different from their rates of past tense overregularization, and noun plurals, like verb past tenses, follow a U-shaped developmental curve in which correct irregulars precede the first overregularized forms. These facts suggest that plural and past tense overregularizations are caused by similar underlying processes. The results pose challenges to connectionist models, but are consistent with Marcus et al.'s (1992) blocking-and-retrieval-failure model in which regulars are generated by a default rule while irregulars are retrieved from the lexicon.

Fernald and her colleagues have argued for the universality of prosodic modifications in speech addressed to infants (e.g. Fernald, 1987; Fernald, Taeschner, Dunn, Papousek, de Boysson-Bardies & Fukui, 1989). An alternative proposal in Bernstein-Ratner & Pye (1984) and Pye (1986) argues that speech modifications to children are the result of a set of conventions that may vary from culture to culture. This note presents arguments against Fernald and in support of the cultural account of prosodic modifications to infants and children. First, in response to criticisms in Fernald et al., data are presented which defend the conclusion in Bernstein-Ratner & Pye that Quiché mothers show less prosodic modification to children than do mothers in other cultures studied to date. Second, data used to support the universal position in Fernald (1987) on adult identification of infant affective states are reinterpreted and shown to be equally interpretable as the result of a set of culturally transmitted rules.

Vocabulary development of three children (aged 1;6–1;8 at the start of the study) who had not begun to evidence a vocabulary spurt even though their productive vocabularies already included well over 50 words was followed to determine if these children eventually would have a vocabulary spurt. All three children evidenced a spurt, beginning at a mean productive vocabulary size of 112 words. The vocabulary spurt occurred at about the same time as the children first demonstrated the ability to sort objects exhaustively and to fast map new object names. Results are discussed in the context of Goldfield & Reznick's (1990; Reznick & Goldfield, 1992) argument that a substantial proportion of children never evidence a vocabulary spurt.