Previous research has shown that children go through a stage in which they know that the number words each refer to a distinct numerosity, yet do not know WHICH numerosity each number word picks out (Wynn, 1992). How do children attain this level of knowledge? We explore the possibility that particular properties of how number words are used within sentences inform children of the semantic class to which they belong. An analysis of transcripts of the spontaneous speech of three one- and two-year-old children and their parents (from the CHILDES database; MacWhinney & Snow, 1990) suggests that the relevant cues are available as input in parents' speech to children, and that children generally honour these properties of number words in their own speech. Implications of this proposal for word learning more generally are discussed.

This paper investigates the similarities and differences observed in individual approaches to the linguistic organization of narrative. Twenty subjects in each of five age groups (four, six, eight, ten years and adult) were asked to relate a narrative elicited from a picture book. All references to the animate characters in the book were coded for form (nominal/pronominal), and function (switch versus maintenance). Individual analyses of the narratives indicated that a variety of strategies were used across all age groups. Strategies identified included thematic subject, nominal and anaphoric. When the narrative was divided into segments based on the referential load of each segment, it was found that there was an interaction between the strategy adopted in the first segment, the age of the subject and the referential load of subsequent segments. A variety of strategies was adopted by all age groups although there were preferential trends observable within each group. The ability to maintain a strategy across the varying referential load of the narrative increased with age. Five developmental stages were identified from the analysis which enabled certain tentative predictions to be made about the way children approach a complex narrative task, suggesting that children pass through a number of stages which reflect their ability to organize the referential content of the narrative at differing speech levels.

This paper examines naturalistic samples of adult-to-child speech to determine if variations in the input are consistent with reported variations in the proportions of nouns and verbs in children's early vocabularies. It contrasts two PRO-DROP languages, Italian and Mandarin, with English. Naturalistic speech samples from six 2;0 English-, six 1;11 Italian-, and ten 1;10 Mandarin-speaking children and their caregivers were examined. Adult-to-child speech was coded for the type frequency, token frequency, utterance position, and morphological variation of nouns and verbs as well as the types and placements of syntactic subjects and the pragmatic focus of adult questions. Children's spontaneous productions of nouns and verbs and their responses to adult questions were also examined. The results suggest a pattern consistent with the children's spontaneous production data. Namely, the speech of English-speaking caregivers emphasized nouns over verbs, whereas that of Mandarin-speaking caregivers emphasized verbs over nouns. The data from the Italian-speaking caregivers were more equivocal, though still noun-oriented, across these various input measures.

The use of the mutual exclusivity constraint was examined in three-year-old and six-year-old children who were either monolingual in English (N=32) or bilingual in English/Urdu (N=32) or in English/Greek (N=32). Three tests of the constraint were used: disambiguation, rejection, and restriction. On the disambiguation test, the mutual exclusivity bias was significantly more evident in five- and six-year-old monolingual children than in their same-age bilingual peers. Monolingual children were also more likely than bilingual children to reject a new name for a familiar object. However, using a restriction test, neither monolingual nor bilingual children readily accepted and restricted typical names for hybrid objects. Developmental differences were also found, as older (five- to six-year-old) monolingual children's responses on the tests were generally more consistent with the constraint than younger (three- to four-year-old) children's responses. Nevertheless, bilingual children did use the constraint, but not to the extent of monolingual children.

This paper presents a longitudinal study on the acquisition of first, second, and third person pronouns in twelve French-speaking and twelve English-speaking children. Comprehension and production data were collected every two months, beginning when the subjects were aged 1;6 and ending once pronouns were fully acquired. Three hypotheses concerning the rules children develop in learning pronouns were tested: (1) the person-role hypothesis (Charney, 1980), (2) the speech-role hypothesis (Clark, 1978), and (3) the name hypothesis (Clark, 1978). An analysis of children's pronominal confusion when they were addressed listeners as well as when they were non-addressed listeners was performed. The results indicated that the mastery of pronouns did not follow the developmental sequence predicted by the speech-role hypothesis; they provided evidence for the person-role hypothesis only when children were speakers, and partially supported the name hypothesis. The data also suggested that pronominal confusion is not a rare phenomenon among children tested in a non-addressee context. Finally, effects of child gender and native language were observed. Possible interpretations of the data are discussed.

The present paper reports on the phonological form of one child's productive vocabulary from age 0;10 to 1;8 with primary focus on his production of multisyllabic targets. A large percentage of his multisyllabic vocabulary was produced as one syllable until the age of 1;6. This limitation was not due to a tendency to extract only single syllables from the speech stream, but rather due primarily to a limitation on production. While some portion of his one-syllable productions could be interpreted as the result of single syllable extraction, a sizeable portion affirmed that he extracted the target size correctly by his inclusion of first and final target phonemes in his productions (e.g. [po] for piano and [kiz] for candies). The resolution of this limitation coincides with his move toward two-word speech. We conclude that there is a developmental and perhaps maturational limitation in the capacity to carry out the processes underlying word and sentence production.

Although much research has investigated children's use of metaphoric language, methodological concerns raise questions about the conclusions, and it remains unclear whether preschoolers can produce metaphors. These studies employed a new methodology to test children's ability to produce metaphors incorporated into metaphoric compounds. In two studies, 59 children aged 2;8–4;3, 63 children aged 4;4–6;1, and 34 adults participated in elicited production tasks. In Study 1, subjects in the COMPOUND condition corrected a puppet's incorrect compound labels for pictures that had metaphoric resemblances to other objects (e.g. ‘leaf-bug’ for a bug shaped like a stick). Subjects in the NON-METAPHORIC condition heard incorrect compounds describing pictures without obvious metaphoric resemblance (e.g. ‘leaf-bug’ for a round black beetle). Children in the REVERSAL condition heard compounds with nouns reversed (e.g. ‘bug-leaf’ for the stick-bug) to discover whether children distinguished between the literal and metaphoric labels. Study 2 provided an additional test of children's metaphoric–literal distinction. Results showed that children as young as 3;0 produced intentional, appropriate metaphors incorporated into compound nouns when the stimuli and puppet's labels primed recognition of metaphoric similarity and compound production. Moreover, children showed evidence of a distinction between literal and metaphoric labels. The data show that preschool children have an early ability to use metaphoric language but that significant developmental change occurs between the ages of 3;0 and 5;0 as well as beyond 5;0. Additionally, metaphoric language in preschoolers is not limited to single-word renamings.

This paper explores the effects of certain aspects of verb input on verb acquisition. It has been observed that the timing of a verb model affects children's learning of the verb (Tomasello & Kruger, 1992). It has also been observed that the focus of the event to which the verb refers affects the argument structure children assign to the verb (Pinker, 1989). This experiment investigated the interaction between the timing of verb models and the focus of the events to which they refer. Thirty children aged from 2;3 to 3;6 heard two novel verbs, one movement focused and the other result focused. Half heard the verbs before the event (impending condition) and half after it (completed condition). An interaction of verb timing and verb focus was found. The movement verb was learned better in the impending condition and the result verb in the completed condition. The contribution of this finding to our understanding of the processes involved in verb acquisition is considered.

The present study examined the pattern of deletion of final /t/ and /d/ in word final consonant clusters in sixteen three- and four-year-old children and their degree of mastery of phonological and grammatical constraints to answer the following questions: how and when is this variable rule acquired, and how does its acquisition relate to the learning of the categorical rule of past tense formation? Sixteen children were tape recorded in their South Philadelphia day care centre. In addition, eight of their mothers were interviewed in their homes for purposes of comparison.

Results of the study revealed that children as young as three had, for the most part, mastered the phonological constraints on (-t, d) deletion. They matched the adult pattern including the constraint of following pause disfavouring deletion, the only one that has been shown to vary according to geographical dialect. The children also made a consistent and adult-like distinction between the grammatical forms of monomorpheme and weak past tense. Their high rate of deletion in semi-weak verbs, which differs from adult patterns, suggests that the children are demonstrating rule acquisition based on an analysis of verbal inflection.

This study describes English-speaking children's acquisition of voice onset time (VOT), a segmental feature that specifies the timing of word-initial stop consonants, and final-syllable vowel lengthening (FSVL), a suprasegmental feature that influences the timing of vowels. The purpose of the study was to evaluate two hypotheses about the acquisition of speech timing contrasts: a ‘motoric’ hypothesis predicting that children would control the vowel duration contrast earlier than the consonantal one (FSVL before VOT), and a ‘representation’ hypothesis predicting that children would control the contrast represented on the segmental level of linguistic description earlier than the contrast represented on the suprasegmental level (VOT before FSVL). Longitudinal acquisition patterns for both contrasts were compared in ten children between the mean ages of 1;6 and 2;0. The results, indicating that English-speaking children usually acquired VOT before FSVL, are discussed in light of evidence that French-speaking children acquire analogous contrasts in the opposite sequence. The crosslanguage comparisons support limited forms of both the motoric and representation hypotheses. As promising topics for further study, the results also suggested the importance of individual differences, and the variability of timing features in the input.

This study examines individual growth rates in definitional skill over a period of three to six years, for 68 low-income children. Children were asked to define words once a year at school, from kindergarten (youngest administration at 5;3) through fourth grade (oldest administration at 10;10). A plateau was observed between age nine and ten both for percent formal definitions (characterized by presence of a superordinate) and for the quality of formal definitions. The plateau was lower than the theoretical ceiling for these measures. However, the children appear to have attained ‘adult levels’ of definitional skill: forty-seven fourth-graders (aged 9;1 to 10;10) performed higher, on average, than their own mothers when giving definitions. These results support the notion that definitional skill is related to being part of an academic culture: low-income mothers, whose formal schooling is complete, generally do not give oral definitions to simple nouns as well as do their nine- to ten-year-old children.

This paper examines two issues concerning the acquisition of grammatical morphemes: (1) How is the acquisition of grammatical morphemes influenced by prosodic and phonological characteristics of the language being learned? and (2) What sorts of prosodic and phonological properties do grammatical morphemes have that might aid children in applying particular segmentation strategies? To address these issues, we compared the acquisition of grammatical morphemes in a pair of morphosyntactically similar but prosodically different languages, namely Taiwan Mandarin Chinese (TMC) and Taiwanese (TW). We analyse the patterns of realization and omission of a highly frequent subset of grammatical morphemes in six children's speech, recorded between the ages 1;6 and 2;3. The results from the between-language comparisons suggest that rhythmic characteristics of languages can affect segmentation by providing different kinds of prosodic handles for children to grasp at.

A fundamental question of child language acquisition is children's productivity with newly learned forms. The current study addressed this question experimentally with children just beginning to combine words. Ten children between 1;6 and 1;11 were taught four new words, two nouns and two verbs, over multiple sessions. All four words were modelled in minimal syntactic contexts. The experimenter gave children multiple opportunities to produce the words and made attempts to elicit morphological endings (plural for nouns, past tense for verbs). Overall, children combined the novel nouns productively with already known words much more often than they did the novel verbs – by many orders of magnitude. Several children also pluralized a newly learned noun, whereas none of them formed a past tense with a newly learned verb. A follow-up study using a slightly different methodology confirmed the finding of limited syntactic productivity with verbs. Hypotheses accounting for this asymmetry in the early use of nouns and verbs are discussed.

Investigation of children's understanding of the cognitive verb forget has shown that young children do not consider the role of prior knowledge when using this verb. Thus, someone may be said to have forgotten a fact despite not ever having previously known it. However, forget can also be used to refer to a failure to recall a prior intention. Three experiments examined the role of prior intention as well as prior knowledge in the comprehension of forget by 160 young children aged four to eight years. The results showed that children initially have two interpretations of forget: as an unfulfilled desire rather than a failure to recall a prior intention, and as a state of not knowing rather than a failure to recall prior knowledge. Explanations for the late comprehension of forget are discussed in terms of representation of knowledge and intention, processing capacity and exposure to pragmatic usages.

The ability to generalize verbs to new examples of previously labelled events demonstrates an implicit understanding that verbs are representative symbols of categories of events. The present study examined when and how very young children generalize familiar verbs to novel events by using the preferential looking paradigm. Overall, 24 children aged 1;8 and 25 children aged 2;2 demonstrated their understanding of the verbs kick and pick-up by looking significantly longer at the target events on control trials. Additionally, children aged 1;8 with the largest expressive vocabulary generalized the same verbs to actions with different agents, but not to actions differing in outcome or manner of action. In contrast, children aged 2;2 consistently extended familiar action verbs to other actions differing in agent or manner, regardless of the size of their expressive vocabulary. These findings were not due to the saliency of any of the actions used and are interpreted in terms of representational change consistent with the acquisition of lexical learning principles.

This paper considers cross-linguistic findings concerning the early development of formal, arbitrary, grammatical systems in normal hearing and deaf children and in children with congenital brain abnormalities. The paper reviews evidence showing an early acquisition of grammatical forms. Such learning is typically dissociated from the development of the relevant semantics. Form–function correspondences were not required for the development of morphological paradigms and for certain aspects of formal syntax. This finding held across all the populations studied.

It is hypothesized that the autonomous nature of these formal paradigms accounts for their priority in learning cross-linguistically.

The purpose of this research was to investigate the potential interaction of conceptual representations and linguistic systems in the process of language acquisition. Language–thought interactions were studied in 80 American, 48 Finnish and 48 Polish preschool children. The research focused on the conceptual and linguistic development of space and time. The spatial and temporal conceptual tasks were designed to measure the transition from experiential to inferential knowledge of space/time representations. In the linguistic domain, comprehension and production tests were used to evaluate the children's capacity to understand mono- and bi-referential location in space and time, where mono-referential location involves a single referent object/event with intrinsic properties (e.g. in/on or past/non-past), and bi-referential location requires two or more referent objects/events and relative perspective (e.g. deictic front/back or before/after). The conceptual and linguistic tests revealed significant changes during the period from two to five years of age, and measures of conceptual development were correlated with measures of linguistic development. As spatial and temporal representations became more structured, children were able to move from mono- to bi-referential location. In a comprehension test, we discovered an interaction of language by dimension. Finnish children found spatial distinctions relatively easy and Polish children found temporal distinctions relatively easy. This interaction was expected on the basis of the relative complexity of the morpho-syntactic coding in the spatial and temporal systems of the two languages. However, the argument relating the timing of acquisition to the transparency versus opacity of the linguistic systems was not supported by the English language comparison. Finally, the Finnish children were relatively better able to accomplish the spatial conceptual tasks as compared to the Polish children. This finding is consistent with a developmental concept of linguistic relativity. In general, the research indicates that spatial and temporal linguistic systems and representational knowledge interact during development with the influence occurring in both directions.

The present study was conducted to assess the effect of didactic techniques used during storybook reading on young children's acquisition of new vocabulary introduced in storybooks. Thirty children for each group of three- and four-year-old children were read one storybook individually. The study included three storybook reading conditions: single-reading, repeated-reading and questioning. In both the repeated-reading and the questioning conditions, the storybook was read three times. Children in the questioning condition were asked, during each reading of the storybook, to label target items with the novel words. Listening to multiple readings of a storybook facilitated children's acquisition of expressive and receptive vocabulary, whereas answering questions during the multiple readings was more helpful to the acquisition of expressive than receptive vocabulary. These findings suggest that, under certain conditions, didactic techniques used by adults have differential effects on preschoolers' receptive and expressive vocabulary.

This study examines mealtimes of preschoolers' families to determine whether rare words are used in informative ways so that a child could learn their meanings. Is there an association between informative use of rare words and the child's later vocabulary? Each use of rare words in 160 transcripts was coded for whether it was informative or uninformative. Each informative exchange was coded for type of strategy used to provide support: physical or social context, prior knowledge, and semantic support. There were 1,631 exchanges around rare words. About two-thirds of these exchanges were informative uses from which the child could learn the word's meaning. The most frequent strategy used was semantic support, accounting for two-thirds of strategies used. The frequency of use of rare words was positively correlated with age-five and age-seven PPVT scores.