Nearly all theories of language development emphasize the importance of distributional cues for segregating words and phrases into syntactic categories like noun, feminine or verb phrase. However, questions concerning whether such cues can be used to the exclusion of referential cues have been debated. Using the headturn preference procedure, American children aged 1;5 were briefly familiarized with a partial Russian gender paradigm, with a subset of the paradigm members withheld. During test, infants listened on alternate trials to previously withheld grammatical items and ungrammatical items with incorrect gender markings on previously heard stems. Across three experiments, infants discriminated new grammatical from ungrammatical items, but like adults in previous studies, were only able to do so when a subset of familiarization items was double marked for gender category. The results suggest that learners can use distributional cues to category structure, to the exclusion of referential cues, from relatively early in the language learning process.

The types of gesture+speech combinations children produce during the early stages of language development change over time. This change, in turn, predicts the onset of two-word speech and thus might reflect a cognitive transition that the child is undergoing. An alternative, however, is that the change merely reflects changes in the types of gesture+speech combinations that their caregivers produce. To explore this possibility, we videotaped 40 American child–caregiver dyads in their homes for 90 minutes when the children were 1;2, 1;6, and 1;10. Each gesture was classified according to type (deictic, conventional, representational) and the relation it held to speech (reinforcing, disambiguating, supplementary). Children and their caregivers produced the same types of gestures and in approximately the same distribution. However, the children differed from their caregivers in the way they used gesture in relation to speech. Over time, children produced many more REINFORCING (bike+point at bike), DISAMBIGUATING (that one+point at bike), and SUPPLEMENTARY combinations (ride+point at bike). In contrast, the frequency and distribution of caregivers' gesture+speech combinations remained constant over time. Thus, the changing relation between gesture and speech observed in the children cannot be traced back to the gestural input the children receive. Rather, it appears to reflect changes in the children's own skills, illustrating once again gesture's ability to shed light on developing cognitive and linguistic processes.

Several descriptions of the transition from single to multiword utterances use prosody as an important diagnostic criterion. For example, in contrast to successive single-word utterances, ‘real’ two-word utterances are supposed to be characterized by a unifying intonation contour and a lack of an intervening pause. Research on the acquisition of prosody, however, revealed that control of the phonetic parameters pitch, loudness, and duration is far from complete at such an early stage. In this study, we examine the interaction between the development of different types of syntactic structures and their prosodic organization. Data from a detailed production record of a monolingual German-learning boy is analysed both auditorily and acoustically with a focus on four different types of two-word utterances produced between 2;0 and 2;3. Two major findings are reported here. First, the different types of two-word utterances undergo individual trajectories of prosodic (re-)organization, in part depending on the time course in which they become productive. This suggests that different types of multiword utterances become prosodically fluent at different points in time. Second, the variability of prosodic features such as pauses and stress pattern is very high at the onset of combinatorial speech. Consequently, fluency or disfluency of individual examples should not be used as a reliable criterion for their syntactic status and we recommend caution when taking prosody as a cue for syntactic development.

Since this is the last issue which I shall edit for the Journal, I would like to express my thanks to authors, reviewers and members of the Editorial Board, to Patrick McCartan and Gwenda Edwards at CUP and to Clive Jenkins, the copyeditor, for their efforts over the past nine years. Very special thanks go to the team of Associate Editors, past and present, the book reviews editor, the statistics consultant and Jo Lewis, the editorial assistant, who has worked with me for almost the entire period of my editorship. Their commitment to the Journal and our discipline and their hard work has made the job not only possible but also enjoyable.

The study explored early syntactic development, and tested the hypothesis that children use similarity of meaning in order to move beyond the learning of individual item-based multiword constructions. The first 6 types of verb–object (VO) constructions in Hebrew-speaking children were analysed for the occurrence of transfer of learning and facilitation, as well as for the semantic similarity of the direct objects (DO). Longitudinal naturalistic speech corpora of 20 children (1;06–2;06) were analysed. We found facilitation (increased rate of learning) among the first 6 types of VO constructions (each type built on a different verb) as evidenced by the accelerating growth curves. Next, we measured the semantic similarity of the DOs using an 8-category system including Patient, Theme and Object of Result. The first 6 DO types represented 3·95 different semantic roles. On the average, after the first VO construction was learned, 3 out of the following 5 constructions produced were not preceded by another VO construction where the DO was of the same semantic category. The results indicate that facilitation of learning of early syntax is most probably NOT mediated by semantic similarity.

One of the most influential recent accounts of pronoun case-marking errors in young children's speech is Schütze & Wexler's (1996) Agreement/Tense Omission Model (ATOM). The ATOM predicts that the rate of agreeing verbs with non-nominative subjects will be so low that such errors can be reasonably disregarded as noise in the data. The present study tests this prediction on data from 12 children between the ages of 1;8.22 and 3;0.10. This is done, first, by identifying children who produced a reasonably large number of non-nominative 3psg subjects; second, by estimating the expected rate of agreeing verbs with masculine and feminine non-nominative subjects in these children's speech; and, third, by examining the actual rate at which agreeing verb forms occurred with non-nominative subjects in those areas of the data in which the expected error rate was significantly greater than 10%. The results show, first, that only three of the children produced enough non-nominative subjects to allow a reasonable test of the ATOM to be made; second, that for all three of these children, the only area of the data in which the expected frequency of agreeing verbs with non-nominative subjects was significantly greater than 10% was their use of feminine case-marked subjects; and third, that for all three of these children, the rate of agreeing verbs with non-nominative feminine subjects was over 30%. These results raise serious doubts about the claim that children's use of non-nominative subjects can be explained in terms of AGR optionality, and suggest the need for a model of pronoun case-marking error that can explain why some children produce agreeing verb forms with non-nominative subjects as often as they do.

Most studies on CV co-occurrence patterns in early phonetic development have been based on Indo-European languages. Data from infants learning Mandarin, which has a substantially different phonological system from Indo-European languages, can confirm or refute the findings of previous studies, thus shedding further light on the theoretical bases of CV association. Spontaneous vocalizations were recorded in 45-minute sessions for each of 24 Mandarin-learning infants aged 0;7 to 1;6. In addition, the speech production of 24 caregivers was audio-recorded during their natural daily interactions with the infants at home. Both infants' vocalizations and adults' speech were transcribed and analysed for consonant–vowel co-occurrence patterns. These patterns were similar to those in other language groups, but language-specific patterns were evident by 1;0. Combinations of alveolars+front vowels and velars+back vowels confirm Davis & MacNeilage's (1990, 1995) frame-then-content theory and Clements's (1991) model of unified features for consonants and vowels. However, our finding of a language-specific pattern (labials+back vowels) suggests the need to reexamine the ‘pure frame’ of Davis & MacNeilage and Clements's grouping of labials and rounded vowels.

Previous work on the acquisition of consonant clusters points to a tendency for word-final clusters to be acquired before word-initial clusters (Templin, 1957; Lleó & Prinz, 1996; Levelt, Schiller & Levelt, 2000). This paper evaluates possible structural, morphological, frequency-based, and articulatory explanations for this asymmetry using a picture identification task with 12 English-speaking two-year-olds. The results show that word-final stop+/s/ clusters and nasal+/z/ clusters were produced much more accurately than word-initial /s/+stop clusters and /s/+nasal clusters. Neither structural nor frequency factors are able to account for these findings. Further analysis of longitudinal spontaneous production data from 2 children aged 1;1–2;6 provides little support for the role of morphology in explaining these results. We argue that an articulatory account best explains the asymmetries in the production of word-initial and word-final clusters.

Predictive relations were examined between measures of 20 mothers' behavioural and verbal general and specific responsiveness and intrusive and supportive directiveness and their children's subsequent expressive vocabularies during three developmental periods with endpoints at the beginning, middle, and end of the second year: 0;10 to 1;1, 1;1 to 1;5, and 1;5 to 1;9. Regression analyses, controlling for mothers' utterance frequencies and children's initial lexicons, revealed considerable consistency between reported and observed lexicons but changing patterns of predictive relations with development. During the first period, behavioural, but not verbal, measures of maternal responsiveness and supportive directiveness were positively predictive. In period two, verbal, but not behavioural, measures predicted children's vocabularies, with specific responsiveness and supportive directiveness as positive predictors and intrusive directiveness as a negative predictor. During the final period, mothers' behavioural and verbal responsiveness and behavioural supportive directiveness positively predicted and their verbal intrusive directiveness negatively predicted children's lexical growth.

Thirty middle- to upper middle-class monolingual Dutch speaking families consisting of at least a mother and a father completed the Infant Form ‘Words and Gestures’ of the Dutch adaptation of the MacArthur Communicative Development Inventory for the same child at 1;1. Considerable inter- and intrafamily variation emerged in how two (or three) different reporters who are all presumably close to the child assess a particular child's communicative abilities. The greater the child's communicative ability, as rated by any one reporter, the more differences tended to emerge between reporters. In order to take into account multiple reporters' assessments of the same child, we propose the use of a Cumulative CDI Score that credits the child with the best score for any item on the CDI as checked by any single reporter. We conclude that single reporter CDI reports may underestimate the child's communicative knowledge.

Situated within the framework of the conceptual metaphor theory (Lakoff & Johnson, 1999), this study investigated young children's understanding of metaphorical extensions of spatial motion. Metaphor was defined as a conceptual-linguistic mapping between a source and a target domain. The study focused on metaphors that are structured by the source domain of motion in space (e.g. time flies by, ideas pass through one's mind, sickness crawls through one's body). The study investigated whether metaphor comprehension varied by the age of the participant, target domain of the metaphorical mapping, and the conventionality of the linguistic form with which the metaphor was conveyed. Data were gathered using a story comprehension task and a semi-structured interview from 60 monolingual Turkish-speaking children, at the mean ages 3;6, 4;5 and 5;5 (20 participants per age group), and 20 adult native speakers of Turkish. The results showed metaphor understanding to be an early emerging cognitive and linguistic capacity.

Properties of the input, such as raw frequency and syntactic diversity, have been shown to play a role, to different extents, in the acquisition of nouns and verbs. This study investigated the relationship between three properties of the input (input frequency, syntactic diversity, and variety in noun-type co-occurrence) and age of acquisition of English adjectives. In addition, this study explored the relationship between adjectival semantic typology and order of acquisition. The data are 7262 child utterances and 6318 maternal utterances containing one of 272 adjective in the language samples of two children, Sarah and Adam, from age 2;3 to 5;0 (Brown, 1973) available in CHILDES (MacWhinney, 2000). Statistical analyses revealed that all three properties of the input were significantly correlated with age of acquisition, but variety in noun-type co-occurrence was not a significant predictor once input frequency and syntactic diversity were taken into account. Semantic analyses revealed that the distribution of adjective types and tokens differed between the children and the mothers (to an extent) when the data were examined in terms of adjectival semantic types. The results suggest that both properties of the input and the semantic properties of the English adjective class play a role in its acquisition.

Research in diachronic linguistics has shown that homonyms are often dispreferred in language. This study proposes that this trend is mirrored in the difficulties that children encounter in mapping homonyms. Two experiments are presented in support of this proposition. In Experiment 1, 16 preschool children (mean age=4;6) are shown to perform quite well on tasks requiring them to assign novel meanings to nonsense words. They perform poorly, however, on tasks requiring them to assign a different, unrelated meaning to a known word. Experiment 2 (N=18, mean age=4;5) shows that preschoolers' performance on this task, however, improves when a known word appears in a syntactic frame that is not appropriate for the word (as when a verb appears in a noun syntactic frame), thereby providing a strong indication that a new meaning is appropriate.

This research addresses the question of why some children are disposed to making a large number of pronoun case errors and others are not. The answer proposed is that when pronoun paradigm building outstrips the development of INFL, children become especially vulnerable to erring in the choice of pronominal word form, resulting in pronoun case error. On the other hand, when pronoun paradigm building proceeds more conservatively, the risk of error is reduced. The spontaneous sentence production of children observed in naturalistic caregiver – child interaction from a cross-section of 44 children (2;0–4;0) is used to support this proposal. The data show that pronoun case error was minimal among children who had strong INFL. However, among children with weak INFL there was a wide range of variation, some children making many errors and others making none. Analysis of variance confirmed that this variation was strongly related to the dispersion of production attempts across an extended pronoun paradigm, such that, the fewer cells attempted, the lower the error rate. These findings show that pronoun case errors are not an inevitable result of grammatical development, but may conceivably be avoided altogether if paradigm building proceeds at a rate commensurate with the child's development of INFL.

The relationship between grammatical and lexical development was compared in 233 English and 233 Italian children aged between 1;6 and 2;6, matched for age, gender, and vocabulary size on the MacArthur Communicative Development Inventories (CDI). Four different measures of Mean Length of Utterance were applied to the three longest utterances reported by parents, and to corrected/expanded versions representing the ‘target’ for each utterance. Italians had longer MLUs on most measures, but the ratio of actual to target MLUs did not differ between languages. Age and vocabulary both contributed significant variance to MLU, but the contribution of vocabulary was much larger, suggesting that vocabulary size may provide a better basis for crosslinguistic comparisons of grammatical development. The relationship between MLU and vocabulary size was non-linear in English but linear in Italian, suggesting that grammar ‘gets off the ground’ earlier in a richly inflected language. A possible mechanism to account for this difference is discussed.

This is a study of the lexical and grammatical abilities of 16 lexically precocious talkers. These children, aged 2;0 were compared to their age-matched peers, 22 typical talkers aged 2;0, and their expressive vocabulary-matched peers, 22 typical talkers aged 2;6. Individual differences in children's lexical knowledge at 2;0 were stable – evident in parent report, laboratory observation, and an experimental fast-mapping paradigm. In accordance with the continuity hypothesis, the lexically precocious children were also grammatically precocious, having a greater representation of grammatical types and tokens and more advanced combinatorial language than their typical age-matches. Their grammatical development was very similar to that of their older vocabulary-matched peers. Limits on continuity were highly constrained with no true dissociation between the lexicon and the grammar in 33 cases examined. We conclude that, among two-year-olds, grammatical development is more tightly associated with the size of the lexicon than with chronological age.

Two experiments investigated the acquisition of English comparative adjective forms, Adj+er and more Adj. In Experiment 1, 72 children, four- and seven-years-old, indicated their preferences for the synthetic or periphrastic comparative form for 16 adjectives in a forced-choice judgement task; their responses were compared to those of a group of adults (Graziano-King, 2003). In Experiment 2, a group of 29 children, ranging in age from 5;1 to 10;9, and a group of 11 adults performed a forced-choice judgement task, similar to that of Experiment 1, and an elicited production task, responding to the same 32 adjectives for both tasks. The two studies together support an acquisition trajectory of three stages. In the first stage, children show no preference for either form of the comparative; in the second, they adopt a suffixation rule; and in the third, they abandon the general rule and become conservative learners, eventually reaching the adult target.

Two construals of agency are evaluated as possible innate biases guiding case-marking in children. A BROAD construal treats agentive arguments of multi-participant and single-participant events as being similar. A NARROWER construal is restricted to agents of multi-participant events. In Hindi, ergative case-marking is associated with agentive participants of multi-participant, perfective actions. Children relying on a broad or narrow construal of agent are predicted to overextend ergative case-marking to agentive participants of transitive imperfective actions and/or intransitive actions. Longitudinal data from three children acquiring Hindi (1;7 to 3;9) reveal no overextension errors, suggesting early sensitivity to distributional patterns in the input.

Three experiments investigated the ability of eight-year old children with poor language comprehension to produce past tense forms of verbs. Twenty children selected as poor comprehenders were compared to 20 age-matched control children. Although the poor comprehenders performed less well than controls on a range of tasks considered to tap verbal-semantic abilities, the two groups showed equivalent phonological skills. Poor comprehenders performed as well as control children when asked to inflect novel verbs and regular verbs. In contrast, poor comprehenders were less skilled than controls at inflecting both high frequency and low frequency irregular verbs. Although the predominant error pattern for all children was to over-regularize, this was most marked in the poor comprehenders; control children were more likely to produce errors that contained knowledge of the irregular form than poor comprehenders. In addition, the ability to inflect irregular verbs was related to individual differences in verbal-semantic skills. These findings are discussed within a framework in which verb inflection is related to underlying language skills in both the phonological and semantic domains.

Auxiliary syntax is recognized to be one of the more complex aspects of language that children must acquire. However, there is much disagreement among researchers concerning children's early understanding of auxiliaries, with some researchers advocating a relatively abstract grammar as the basis for auxiliary syntax, while others view the acquisition of auxiliary syntax as the gradual accumulation of linguistic knowledge, initially tied to individual lexical items. To investigate the status of children's early knowledge of auxiliary syntax, two studies were carried out. In study 1, 28 children (M=3;1) were tested for their use of the auxiliaries BE and HAVE in declaratives, while in study 2, 19 children (M=3;3) were tested for their use of these auxiliaries in questions. Although overall error rates were low, there were differences between BE and HAVE in the proportion and types of errors observed in declaratives and questions, and some individual children showed very high error rates. The implications of these findings for different models of auxiliary syntax in children's early utterances are discussed.