Six children were visited in their homes every two weeks for 18 months from the age of six months in order to observe their developing comprehension and production of words. Controlled testing of the children's developing vocabulary was also carried out to provide a more detailed picture of the precise context in which a word was understood or produced. The results showed both similarities and individual differences among the children in patterns of early comprehension. For all six children there was a very close relationship between early production and comprehension of words: words that were contextually flexible in production tended also to be so in comprehension and words that were context-bound also tended to be so in both modalities although there was some evidence that the two types of word differed in the extent to which comprehension preceded production. All children were also similar in showing evidence of contextually flexible comprehension very early on. However, there were individual differences both in the rate at which comprehension developed and in the lag between comprehension and production. The significance of this pattern of development for accounts of lexical development is explored.

Little is known about the acquisition of phonology by children learning Cantonese as their first language. This paper describes the phoneme repertoires and phonological error patterns used by 268 Cantonese-speaking children aged 2;0 to 6;0, as well as a longitudinal study of tone acquisition by four children aged 1;2 to 2;0. Children had mastered the contrastive use of tones and vowels by two years. While the order of acquisition of consonants was similar to that reported for English, the rate of acquisition was more rapid. The developmental error patterns used by more than 10% of children are also reported as common in other languages. However, specific rules associated with Cantonese phonology were also identified. Few phonological errors were made after age four. The results are consistent with the hypothesis that the ambient language influences the implementation of universal tendencies in phonological acquisition.

This study investigated overextensions in comprehension and production using a new method (the preferential-looking paradigm) in which children (N = 99, mean age (younger) = 1;9, mean age (older) = 2;3) were asked to find the referent that matched the label they were given. Both Real Referent (in which there was a match) and Anomalous (in which there was no match) trials were included, as well as nonverbal control trials. During the Real Referent trials, all children significantly preferred the matching puppet. During the Anomalous trials, children showed no preference with two of the labels (dog and cat); however, they did show a preference when ‘cow’ was requested but not available. There were no differences based on prior overextension performance in production. It is concluded that overextensions in production are not diagnostic of children's underlying semantic representations, and that anomalous trials in comprehension provide useful information concerning young children's lexical entries.

This cross-linguistic study investigates children's early lexical development in English and Korean, and compares caregivers' linguistic input in the two languages. In Study 1, the lexical development of nine Korean children was followed from 1;2 to 1;10 by monthly visits and maternal reports. These Korean data were compared to previously collected English longitudinal data. We find that: (1) Korean children as young as 1;3 use verbs productively with appropriate inflections. (2) Seven of the nine children show a verb spurt at around 1;7; for six of these children the verb spurt occurs before the noun spurt. No such early verb spurt is found in the English data. Unlike in English, both verbs and nouns in Korean are dominant categories from the single-word stage. (3) Korean children express language-specific distinctions of locative actions with verbs. Study 2, a crosslinguistic study of caregivers' input in English and Korean, shows that Korean mothers provide more action verbs but fewer object nouns than American mothers. Also, Korean mothers engage in activity-oriented discourse significantly more than American mothers. Our study suggests that verbs are accessible to children from the beginning, and that they may be acquired early in children who are encouraged to do so by their language-specific grammar and input.

Fourteen full-term, healthy, three-month-old infants were observed during a total of 15 minutes spontaneous face-to-face interaction with their mothers. Facial and manual actions, gaze direction and vocalizations were coded. The infants' cooing vocalizations were categorized into syllabic and vocalic sounds. Index-finger extension occurred frequently in sequence with syllabic sounds, which are speech-like vocalizations, but rarely occurred in sequence with vocalic sounds. No other categories of nonvocal behaviours showed such a relationship. In a subsequent experiment, the infants experienced either conversational turn-taking or random responsiveness from their mothers. In the turn-taking condition, the infants produced a higher ratio of syllabic to vocalic sounds, and a higher frequency of index-finger extension. These results suggest a strong connection between speech and the pointing gesture long before the infant can actually talk.

This study explored the development of verbal behaviours of infants during two mother–infant games. Twenty-five infants were videotaped as they played peek-a-boo and ball with their mothers at 0;6, 0;9, 1;0, 1;3, 1;6, and 2;0. The frequencies of eight categories of vocal/verbal behaviours were analysed as they evolved over time in both games. Despite differences in the structure and level of difficulty of peek-a-boo and ball, the development of these behaviours proved to be similar in the two games. One category, PRIMITIVE VOCALIZATIONS, which did not change in frequency over time, was seen to have a pragmatic rather than a linguistic function. Another category, PRELEXICAL COMMENT, demonstrated an early capacity for conveying topic and comment together in the form of speech sounds combined with an attentiongetting gesture well before the emergence of multiple-word utterances. The vocal behaviours produced during games were compared with the results of language tests administered during the experimental sessions. Strong correlations were found between the results of these two measures of language. The predictive nature of vocal behaviours during games is discussed.

It is often assumed that children go through a stage in which they systematically overapply irregular past tense patterns to inappropriate verbs, as in wipe-wope, bring-brang, trick-truck, walk-has walken. Such errors have been interpreted both as reflecting over-use of minor grammatical rules (e.g. ‘change i to a’), and as reflecting the operation of a connectionist pattern associator network that superimposes and blends patterns of various degrees of generality. But the actual rate, time course, and nature of these errors have never been documented. We analysed 20,000 past tense and participle usages from nine children in the CHILDES database, looking for overapplications of irregular vowel-change patterns, as in brang, blends, as in branged, productive suffixations of -en, as in walken, gross distortions, as in mail-membled, and double-suffixation, as in walkeded. These errors were collectively quite rare; children made them in about two tenths of one per cent of the opportunities, and with few stable patterns: the errors were not predominantly word-substitutions, did not occur predominantly with irregular stems, showed no consistency across verbs or ages, and showed no clear age trend. Most (though not all) of the errors were based closely on existing irregular verbs; gross distortions never occurred. We suggest that both rule-theories and connectionist theories have tended to overestimate the predominance of such errors. Children master irregular forms quite accurately, presumably because irregular forms are just a special case of the arbitrary sound-meaning pairings that define words, and because children are good at learning words.

Theoretical arguments for considering production as a source of input for analysis (the OUTPUT-AS-INPUT hypothesis) are reviewed, and empirical evidence supporting this hypothesis is presented. The evidence consists of a longitudinal study of the developmental course of a self-created form, produced by one Dutch child. This form is the product of blending two words, wat and iets, to yield unitary wat-iets. In Dutch, independent wat and iets may each mean ‘some’ and/or ‘something’. Though wat-iets is not permitted by the language, and so does not occur in environmental input, the form stays in the child's repertoire for about 10 months (between 3;8 and 4;7) and is apparently subjected to processes of generalization: first the child treats wat-iets as a two-word frame that may be regularized, later as a unitary word that may be semantically extended. After the extension of wat-iets, independent synonymous wat and iets appear for the first time in the child's speech. It is argued that the child actually analysed his own creation.

Twelve children (five boys and seven girls, mean age 4;1) interacted with their mothers in two conversational settings: playing with a favourite toy and helping to prepare lunch or muffins. The percentage of two topic continuation processes – topic incorporation and collaboration – used by mothers and children was analysed. It was hypothesized that the help setting with a predetermined structure would elicit a greater percentage of topic incorporation by the dyads than the play setting. In fact, the play setting elicited a greater percentage of topic incorporation from mothers than the help setting. Children did not differ significantly in the percentage of use of topic incorporation between the two settings, but appeared to be equally proficient in incorporating topics in settings with and without a predetermined structure. The play setting also elicited more topic collaboration from the children than the help setting. While the help setting appeared to support collaborative action, the play setting permitted the dyads to be informative about the toys as well as related topics. Therefore, the two settings provided different opportunities for the dyads to continue topics.

The present study examines adult and child word-initial voice onset time productions in English and Hindi (10 adults and 20 children in each language) to determine the age of acquisition of the phonemic voice contrast. Cross-linguistic differences in patterns of acquisition were found, but these need not be traced to the different phonological Systems per se. An examination of the data indicates that the best predictor of age of voice contrast acquisition across languages is one which rests on the actual acoustic differences between members of phonologically contrastive pairs. In general it was found that the larger the post-release voice onset time differences between pair members in the adult model, the earlier the contrast is reliably produced by child language learners.

Spontaneous speech samples from children during the period of transition from one word to multi-word utterances in interaction with their French-speaking mothers were explored in order to study the appearance and development of functional changes in their use of language. Two types of such change were noted in the longitudinal records of four children when they were still essentially one-word speakers: the beginnings of references to the past, and the appearance of explanations and justifications, especially in communicative situations of request and refusal. The co-appearance of these behaviours is discussed in relation to two more general developmental changes: a detachment from the immediately perceptible situation linked to a further elaboration of the signifier-signified relation, and a socio-cognitive development leading to a view of the interlocutor as an alter ego, as a person whose psychological states may be different from the child's own.

This paper presents a study of the spontaneous pre-sentential negations of ten English-speaking children between the ages of 1;6 and 3;4 which supports the hypothesis that child English nonanaphoric pre-sentential negation is a form of metalinguistic exclamatory sentence negation. A detailed discourse analysis reveals that children's pre-sentential negatives like No Nathaniel a king (i) are characteristically echoic, and (ii) typically express objection and rectification, two characteristic functions of exclamatory negation in adult discourse, e.g. Don't say ‘Nathaniel's a king’! A comparison of children's pre-sentential negations with their internal predicate negations using not and don't reveals that the two negative constructions are formally and functionally distinct. I argue that children's nonanaphoric pre-sentential negatives constitute an independent, well-formed class of discourse negation. They are not ‘primitive’ constructions derived from the miscategorization of emphatic no in adult speech or children's ‘inventions’. Nor are they an early derivational variant of internal sentence negation. Rather, these negatives reflect young children's competence in using grammatical negative constructions appropriately in discourse.

English-speaking children (N = 91) who were attending French schools (bilingual group) were given a battery of phonological awareness tests in kindergarten and in grade 1. At the time of kindergarten testing the mean age of the children was 5:9. Their performance was compared to age-matched English-speaking children (N = 72) attending English schools (monolingual group). The bilingual children showed heightened levels of phonological awareness skills in kindergarten in the area of onset-rime awareness. By grade 1, the pattern of group differences was more complex. The monolingual and bilingual children performed similarly on onset-rime segmentation tasks. The monolingual children had higher phoneme awareness scores than their French-schooled peers; this result is interpreted to reflect the role of literacy instruction on phoneme awareness development. In comparison, the bilingual children had higher syllable segmentation scores than their monolingual peers. This result is interpreted to reflect the role of second language input on phonological awareness.

The present studies investigated children's use of verb inflections to guide their initial mapping of verb meanings. Given that children initially apply the progressive -ing inflection to verbs denoting actions and the past -ed inflection to verbs denoting results of events, two studies were conducted to investigate whether children use these inflections during mapping of novel verb meanings. In both studies, subjects were taught novel verbs and were asked to extend those verbs to events in which the action or result differed from events used to teach the verbs. It was predicted that subjects would be less likely to extend verbs inflected with -ing to events with new actions and would be less likely to extend verbs inflected with -ed to events with new results. Eighteeen three- and five-year-olds and 24 adults participated in Experiment 1 in a between-subjects design that produced weak effects for the youngest subjects tested. Experiment 2 tested 16 three-year-olds and 19 five-year-olds in a within-subjects design and produced the predicted effect for three-year-olds, but not for five-year-olds. The findings are discussed in terms of their implications for early verb learning and regarding the use of the bootstrapping construct in language acquisition research.

In the present longitudinal study, we examined changes in parental labelling and infants' categorization skills as potential predictors of vocabulary composition, the age of the naming explosion, and the acquisition of subordinate labels. Sixteen French- and English-speaking parent–child dyads were videotaped during a 2O-minute free-play session every month beginning when the child was 1;0 and ending at 2;0. The children received object-manipulation tasks every three months and their vocabulary growth was recorded. Parental labelling practices were assessed monthly using a picture-book reading task. Both parental labelling and children's categorization skills predicted the content of children's lexicon, with children with more names in their vocabulary having better categorization skills. Furthermore, the naming explosion was found to coincide with improvement of categorization skills. These findings suggest that the influence of each factor varies as a function of the stage and aspect of lexical development considered.

Previous tasks have shown that preschool and early elementary school-children typically have trouble learning and identifying homonyms (Peters & Zaidel, 1980; Mazzocco, 1989). It is possible that a one-to-one mapping assumption or a lack of metalinguistic skills makes homonym learning and identification particularly difficult. In three experiments we examined a total of 60 three-year-olds' ability to pick out homonym pairs, and the extent to which they realize that although homonyms share a common label, they represent two different categories. In Experiment 1 subjects were asked to identify homonym pairs. In Experiment 2, homonym pairs and non-homonym pairs were labelled, then children were asked whether the pairs had the same name, and whether they were the same kind of thing. In Experiment 3 children were shown one-half of each of several homonym and non-homonym pairs, then asked to identify a name match and a category match from a set of pictures. From these experiments we conclude that children have the metalinguistic skills necessary to identify homonym pairs; moreover, they realized that homonyms represent two different categories. Finally, if children have a one-to-one mapping assumption, it is not strong enough to prevent them from acquiring homonyms.

It has been claimed that children simultaneously acquiring two languages go through an initial stage when they are unable to differentiate between their two languages. Such claims have been based on the observation that at times virtually all bilingual children mix elements (e.g. lexical, morphological) from their two languages in the same utterance. That most, if not all, children acquiring two languages simultaneously mix linguistic elements in this way is widely documented. Although such code-mixing is not well understood or explained, there are a number of explanations unrelated to lack of language differentiation that may explain it. Moreover, while language differentiation is widely attested among bilingual children once functional categories emerge, usually during the third year, there is still some question as to how early in development differentiation is present. In this study, we examined language differentiation in five bilingual children prior to the emergence of functional categories (they ranged in age from 1;10 to 2;2 and in MLU from 1·23 to 2·08). They were observed with each parent separately and both together, on separate occasions. Our results indicate that while these children did code mix, they were clearly able to differentiate between their two languages. We also examine the possibility that the children's mixing is due to (a) their language dominance, and (b) their parents' rate of mixing. We could find no evidence that their mixing was due to parental input, but there was some evidence that language dominance played a role.

This study tests the widely-cited claim from Volterra & Taeschner (1978), which is reinforced by Clark's Principle Of Contrast (1987), that young simultaneous bilingual children reject cross-language synonyms in their earliest lexicons. The rejection of translation equivalents is taken by Volterra & Taeschner as support for the idea that the bilingual child possesses a single-language system which includes elements from both languages. We examine first the accuracy of the empirical claim and then its adequacy as support for the argument that bilingual children do not have independent lexical systems in each language. The vocabularies of 27 developing bilinguals were recorded at varying intervals between ages 0;8 and 2;6, using the MacArthur GDI, a standardized parent report form in English and Spanish. The two single-language vocabularies of each bilingual child were compared to determine how many pairs of translation equivalents (TEs) were reported for each child at different stages of development. TEs were observed for all children but one, with an average of 30% of all words coded in the two languages, both at early stages (in vocabularies of 2–12 words) and later (up to 500 words). Thus, Volterra & Taeschner's empirical claim was not upheld. Further, the number of TEs in the bilinguals' two lexicons was shown to be similar to the number of lexical items which co-occurred in the monolingual lexicons of two different children, as observed in 34 random pairings for between-child comparisons. It remains to be shown, therefore, that the bilinguals' lexicons are not composed of two independent systems at a very early age. Furthermore, the results appear to rule out the operation of a strong principle of contrast across languages in early bilingualism.

Thirty-six three-, four- and five-year-olds were asked to select labels for deceptive stimuli (e.g. for an eraser that looked like a pencil). Three types of labelling were investigated –simple (e.g. ‘is an eraser’); appearance-predicated (e.g. ‘looks like an eraser’); and reality-predicated (e.g. ‘is really and truly an eraser’). An age-related appearance-reality shift was observed in simple labelling (e.g. older children were more likely than younger ones to accept eraser and reject pencil as simple names for the pencil-eraser). This trend was robust over method and semantic domain, though weaker with object than with colour labels. As in previous research, older children were more likely than younger ones to map different appearance- than reality-predicated labels onto an item (e.g. to accept that the pencil-eraser looks like a pencil, but is really and truly an eraser); however, all age groups were reluctant to extend more than one name to a stimulus via a common predicate (e.g. to accept two reality-predicated labels for the same object). This one-label-per-predicate pattern was observed more frequently within reality than within appearance predicates; more frequently with colour than with object names, and with questions blocked by predicate than by name. It is argued that younger children maintained this pattern because of inflexible encoding, but that older ones did so because of better understanding of the appearance-reality distinction, greater reality dominance, and a Mutual Exclusivity bias.