Canonical syllables may be important units in early speech perception as well as production. Twenty infants (mean age 51 hours) (and twenty controls) were tested for their ability to discriminate between members of syllable pairs which were either canonical (pæt and tæp) or non-canonical (pst and tsp). A discrimination learning method was used in which syllables signalled the availability of either a recording of the mother's voice or silence – one of which was presented if the infant began a sucking burst. Infants in the canonical condition changed sucking patterns during signals over an 18-minute experimental session and activated their mother's voice more than silence, consistent with previous experiments using mother's voice as a reinforcer. In the non-canonical condition, infants also changed sucking patterns but sucked more during the signal for quiet than mother's voice, contrary to previous findings. Differential sucking during the syllables indicated discrimination in both conditions, but infants responded differently depending upon whether the syllables were canonical or non-canonical. The activation of silence in the non-canonical condition may be the result of a preference for quiet, but it is better explained as a failure to progress to a level of differential responding that was reached by the canonical group.

This study explores the spontaneous acquisition of Italian inflectional morphology by three children (age range 1;4–3;0). Longitudinal, free speech samples are examined, focusing on the development of the morphological paradigms of Italian verbs, pronouns and articles. Data analysis is conducted using criteria appropriate to allow reliable cross-linguistic comparisons with data from English. By this means we evaluate the plausibility of a nativist, parameter-setting account of language development in Italian and English, as recently proposed for these two languages. Results show that the general developmental patterns observed in Italian are not significantly different from those found in English. These findings are not consistent with current interpretations of parameter-setting accounts of language development. Alternative explanatory models are discussed.

The fundamental frequency F0 patterns of maternal speech addressed to infants aged 0;3–0;4 were measured quantitatively. Speech samples were recorded when six Japanese-speaking mothers addressed an adult and their own infants. Japanese mothers speaking to adults use a relatively restricted F0 range, concentrated around the mother's F0, which tends to be near the low end of the total range used. These acoustic characteristics are not altered substantially when these same women speak to their infants in initial utterances to attract the infants' attention. If such attempts are unsuccessful, however, they are likely to make more exaggerated utterances, in which F0 shifts upward and the frequency range is significantly increased. Moreover, only when acoustic characteristics of maternal speech to infants are exaggerated, can the type of F0 contour of the infant's subsequent response be predicted to a significant extent from the mother's preceding utterance.

This investigation focuses upon an outstanding aspect of child phonology – that of consonant harmony, relabelled ‘phonological harmony’ – and inquires whether representational or processing deficits are responsible for its occurrence. A detailed analysis of the oral output of one German-speaking girl (2;7.15–2;11) supports the contention that the Imperfect Processing Model fares much better in accounting for her harmony strategy than the Incomplete Representation Model. It is established that bilabial harmony is the only type of assimilation she has recourse to, and that this process is mainly used to cope with difficult sounds, although it also implicates consonants which do not pose a production problem. The difficult sounds are arguably not absent from the child's system because they can be uttered in some positions though not in others. The harmonizing tendency is interpreted within the interactive activation model of language production and is claimed to emanate from two particularities of her processing system. She has represented even the difficult elements as network nodes, but some connections between the segment and the feature level are ill developed. As a result, activation cannot spread smoothly between these levels and the relevant units cannot be made available for production. In addition, an excessive linkage strength has been built up among the node [bilabial] and all its associates at the segment level. This puts bilabial consonants into a state of hyperactivation and allows them even to intrude upon those segments which have been perfectly mastered. It is finally shown why these two mechanisms are very unlikely to become permanent features of the child's processing system.

This study explores the role that gesture plays in the earliest stages of language learning. We describe how one-word speakers use gesture in combination with speech in their spontaneous communications, and interpret gesture presented in combination with speech in an experimental situation. Forty one-word speakers (ages 1;2.22 to 2;4.6) were videotaped in a free-play session which provided data on the child's spontaneous gesture and speech production. The children were also given a comprehension task in which the presence and absence of gesture were systematically varied in relation to speech. We found that (1) all of the children spontaneously produced gestures in combination with speech, and (2) all of the children were able to understand gesture when it was presented in combination with speech, not only when the gesture was redundant with speech but also when the gesture substituted for speech. These data suggest that, even at this young age, gesture naturally forms an integrated system with speech in both production and comprehension.

The utterances of one French and one American infant at 0;5, 0;8, 0;11, and 1;2 were transcribed and acoustically analysed for syllable duration and vowel formant values. Both general and language-specific effects emerged in the longitudinal study. Initial similarities in the consonantal repertoires of both infants, increasing control in producing target F1 and F2 values, and developmental changes in babbling characteristics over time seem to reflect universal patterns. Yet the babbling of the infants differed in ways that appear to be due to differences in their language environments. Shifts in the infants' sound repertoires reflected phoneme frequencies in the adult languages. The English-learning infant produced more closed syllables, which is characteristic of English, than the French-learning infant. The French-learning infant tended to produce more regularly-timed nonfinal syllables and showed significantly more final-syllable lengthening (both characteristic of French) than the English-learning infant.

Three Canadian–English infants and three Parisian–French infants were filmed bi-weekly for three to five months, from the age of 0;9 or 0;11 until 1;2, at home in naturalistic interaction with a parent. Their babbled utterances were transcribed phonetically and categorized according to consonant-type and vowel-type. The contexts for each utterance were described in terms of both specific and more general contextual categories. Observed frequencies of co-occurrences between phonetic and contextual categories were compared to expected frequencies, and deviations were considered to be patterns in babbling. Patterning increased after age 1;0 for most infants, and from 15% to 30% of each infant's babbled utterances recurred in particular contexts with a greater-than-expected frequency. Similarities in patterns were found both within and across language groups. These sound-meaning correspondences in babbling are viewed as continuous with early situation-bound meaning in words.

Comparison of patterns of cluster realization from 47 children ranging in age from 3;4 to 6;8 with functional (non-organic) speech disorders with those reported in the literature for normal acquisition reveals that these patterns are essentially the same for both groups. Using a two-level generative phonology for children's independent systems, further analysis of cluster realizations by means of feature geometry and under-specification theory reveals that there are systematic and principled relationships between adult representations of clusters and children's underlying representations and between children's underlying representations and their phonetic representations. With special emphasis on coalescence phenomena, it is suggested that the apparent diversity in children's cluster realizations can be reduced to four constraints on the form of underlying and phonetic representations.

English has several classes of transitive verbs which can optionally appear without an undergoer. Despite their similar syntactic sub-categorization, there are at least three different semantic subclasses that allow undergoer omission. Information sources based on surface structure, for example, syntactic bootstrapping, cannot inform the child of the semantic representation of these verbs. The focus of this paper is the acquisition of a single English verb, eat. The transcripts of 40 children, who were audiotaped monthly from 1;0 to 3;0, showed that eat was the first member of this verb class to be acquired. Some 1276 eat sentences were analysed for the presence of overt undergoer arguments across levels of cumulative verb lexicon (CVL) size, and two discourse conditions: (1) UNDERGOER ACCESSIBLE and (2) OPEN (to undergoer omission). Results indicate that undergoer omission became associated with discourse conditions when CVL size rose above 75 types, at MLU approximately 2·4 and age approximately 2;3. This suggests that two-year-old children are sensitive to a relationship between undergoer omission and discourse context.

To examine the possible persistence of phonological selectional constraints on young children's lexical choices, the words attempted in the conversational speech of a longitudinal sample of 12 normally-developing preschoolers from age 2;0 to 5;0 were scored for syllabic length, presence of consonant clusters, and distribution of constituent phonemes. Except at the youngest ages, few developmental changes in target word characteristics were seen, and the observed differences were largely accounted for by syntactic, lexical, and pragmatic factors. The results suggest that selectional constraints persist only briefly in the course of language acquisition.

The existence of stylistic variation between children in the early stages of language acquisition has been most frequently studied using Nelson's 0973) referential—expressive distinction. While the use of this distinction has generated a great deal of interesting research, there are a number of major problems associated with it. The present study presents a simple scheme, based on formal categories, for coding stylistic variation in the early lexicon. When applied to the first 50 and 100 words of 12 children collected between 0; 11 and 2; 3, the major dimensions of difference are found to be the relative proportion of common nouns and the relative proportion of frozen phrases. Moreover, the proportion of frozen phrases is also found to be significantly positively related to children's early productivity, suggesting that, rather than being a ‘deadend’ in early language development, the acquisition of frozen phrases may provide an alternative route into multiword speech.

This study examines the relationship between maternal-report measures of referential vocabulary and observational measures of referential vocabulary and usage in eight first-born middle-class children at 50 and loo words. The results indicate that although maternal-report measures of vocabulary composition can be reasonably reliable, provided some attempt is made to restrict variation in the number of vocabulary items upon which they are based, such measures tend to exaggerate the relative importance of common nouns for the child in two ways; firstly, in the sense that they reflect differential maternal sensitivity to such word-types in comparison with other less-‘referential’ items; and, secondly, in the sense that they overestimate the extent to which such word-types actually occur in the child's spontaneous speech.

In this study, mental terms in mothers' and their children's speech at two and three years of age were studied in order to examine the relationships between maternal and child use. Nineteen mother and child dyads were videotaped for one hour on each of two days when the children were 2;0 and again for two one-hour sessions on separate days when they were 3;0, and mental terms were noted. The utterances in which mental terms were used were coded for function. Results supported the existing picture of children's mental term use. Few terms appeared at 2;0, but many were used at 3;0 with think and know predominating. Mental terms occurred more commonly in utterances used to regulate the interaction between the participants than in utterances referring to mental states. Children's mental term use mirrored that of their mothers. Further, mothers' use of mental terms for particular functions when their children were 2;0 predicted their children's use at 3;0. While allowing no conclusions about causation, our findings suggest that the development of mental state language, and thus presumably a theory of mind, is fostered by the linguistic environment. Specifically, it is argued that the tendency of mothers to focus their children's attention on mental processes by talking about them and, more importantly, by using utterance types which conceivably direct the children to reflect on their own mental states, is associated with children's use of mental terms.

The reported study investigated the relation between children's single-word utterances and maternal single-word utterances expressing similar communicative intents. Twenty-four Hebrew-speaking dyads (the children about 1;6) were videotaped for 30 min in an unstructured session. Single-word utterances were analysed for their communicative intent and the relationship of the expression to the underlying intent was defined in the form of realization rules. Of 17,471 child utterances, 97·0% were realizations that were also used by mothers for expressing the same communicative intent. The most frequently modelled rule for an intent had the highest chance of being adopted by children, and the probability sharply decreased for the relatively less frequently modelled rules. The results suggest that children's single-word utterances are similar to, and probably learned from, single-word utterances of caretakers expressing the same specific communicative intents.

Two studies of verb learning are reported. The focus of both studies was on children in their second year of life learning verbs in various pragmatic contexts. Of particular interest was the comparison of ostensive contexts – in which word and referent were simultaneously present in the child's perceptual field – to non-ostensive contexts. In a naturalistic study of 24 children at 1;3 and 1;9, it was found that mothers modelled verbs for their children most often BEFORE the referent action actually occurred. Over 60% of maternal verbs were used to refer to actions that mothers wished children to perform or that they were anticipating their performing (IMPENDING actions). Some verbs were also used to refer to current actions (ONGOING actions) or actions that had just been completed (COMPLETED actions). Children responded with comprehension most often to impending models. Impending and completed models, but not ongoing models, were correlated with children's verb vocabularies at 1;9. The second study was a lexical training study of 48 two-year-olds. Children learned to produce a novel verb best when it was modelled in the impending condition. They learned to comprehend it equally well in the impending and completed conditions. Children showed no signs of superior learning in the ostensive (ongoing) learning context. Results of the two studies are discussed in terms of the different learning processes involved in acquiring nouns and verbs, and, more broadly, in terms of a social-pragmatic view of language acquisition in which the ostensive teaching paradigm is but one of many contexts in which children learn to establish a joint attentional focus with mature language users.

Young children's slips of the tongue are a rich source of information about developing language processing and storage mechanisms. This paper presents an analysis of 907 slips from 32 children, ages 1;4–6;0, collected in naturalistic settings. It is found that these children make most of the same types and proportions of slips as adults: phonological errors outnumber lexical, which exceed phrasal. In phonological errors, anticipations are most common, followed by perseverations and exchanges; children make more completed anticipations and exchanges than adults, probably due to less mature self-monitoring. Like adults, children make more substitutions than additions or omissions. Children's slips support a theory of speech planning in which propositional, syntactic, intonational, content word, function word and phonological levels have somewhat independent status; however, there is little evidence for a derivational morphology level at this age.

The present paper reports a case-study of a normally developing boy who made pronominal errors for about ten months. Comprehension and production of first- and second-person pronouns were longitudinally examined from 1; 7 to 2; 10 to test three hypotheses concerning pronominal errors: pronominal errors are a result of either (a) semantic confusion, (b) simple imitation, or (c) confusion between self and others. The results showed that the child began using first- and second-person pronouns at about 1; 8 and mastered the correct usage by 2; 10. Consistent errors for the first- and the second-person pronouns were observed from 1; 11 to 2; 4, but proportions of errors occurring in his imitative language were low. The comprehension and production data clearly indicated that the child persistently made pronominal errors due to semantic confusion. That is, first-person pronouns referred to a person with whom the child conversed and second-person pronouns referred to himself.

Sociolinguists have investigated language mixing as code-switching in the speech of bilingual children three years old and older. Language mixing by bilingual two-year-olds, however, has generally been interpreted in the child language literature as a sign of the child's lack of language differentiation. The present study applies perspectives from sociolinguistics to investigate the language mixing of a bilingual two-year-old acquiring Norwegian and English simultaneously in Norway. Monthly recordings of the child's spontaneous speech in interactions with her parents were made from the age of 2;0 to 2;7. An investigation into the formal aspects of the child's mixing and the context of the mixing reveals that she does differentiate her language use in con-textually sensitive ways, hence that she can code-switch. This investigation stresses the need to examine more carefully the roles of dominance and context in the language mixing of young bilingual children.

Seventeen preschool (age range 2;10–3;6), 26 kindergarten (age range 5;5–6;7), and 26 fourth-grade (age range 9;5–10;5) children's knowledge structures were examined with a word association task and a match-to-sample picture task to determine whether or not children used slot-filler categories as a mediating structure between event-based and taxonomic knowledge structures, as proposed by Nelson (1985, 1986). In general, preschool children were able to provide event-based, but not slot-filler or taxonomic, relations; kindergarten children were able to provide event-based or slot-filler relations, but very few taxonomic relations; and fourth-grade children were able to provide all three relations. These findings support Nelson's hypothesis that taxonomic knowledge structures are derived from event-based knowledge structures with the aid of slot-filler categories.

Recent treatments of the optionality of sentence subjects in young-children's English have sought to link this phenomenon, and its eventual demise, to the development of the child's verb inflection system or to a parameter-resetting within the INFL (‘inflection’) constituent of the child's grammar. It is claimed that subject optionality disappears when these developments occur. The case-study reported here investigated the productive language of an English child between 2;5 and 3;0. It found that subjects were no longer optional at a stage when none of the reflexes of INFL claimed in the literature to be associated with the disappearance of subject optionality had yet been acquired. The possibility that subjects were present only when communicatively required was rejected. The frequency of subject realization of a Japanese child aged 3;0 was used to provide a measure of expected realization when subjects are not grammatically required. It is concluded that subject obligatoriness in English may be acquired as a characteristic of the language sui generis, independently of developments elsewhere in the child's emerging grammar.