This study tested whether bilingual children show a lag in semantic development (the schematic–categorical shift) relative to monolingual children due to smaller vocabularies within a language. Twenty French–English bilingual and twenty English monolingual children (seven to ten years old) participated in a picture-naming task in English. Their errors were coded for schematic or categorical relations. The bilingual children made more schematic errors than monolinguals, a difference that was accounted for statistically by vocabulary score differences. This result suggests that within-language vocabulary size is one important factor in semantic development and may explain why bilingual children sometimes show a lag relative to monolingual children in one of their languages, perhaps the language in which they have received less formal instruction.

The present study aimed at investigating the contextual stability, the contextual continuity and the concurrent associations between maternal measures (general language, communicative functions and mind-mindedness) and child measures (total number of word types and tokens) in two different contexts, free-play and mealtime. To this purpose, the interactions occurring between 25 mothers and their 16-month-old children in each context were video-recorded, transcribed and later coded for the selected measures. Significant contextual stability was observed in the mothers’ production of general language measures (total number of utterances, total number of words and MLU), in the children's production of word types and tokens, and in some communicative functions (Tutorial, Control and Asynchronous). No contextual stability was found for the mothers’ production of attuned mind-related comments. For continuity, both mothers and children produced more utterances and words in the free-play than in the mealtime context; the production of attuned mind-related comments and the use of the Control function were also more frequent in the free-play context. Lastly, the analysis of the concurrent correlations indicated that, especially in the mealtime context, the number of words produced by children was positively associated with the number of words produced by mothers and by their use of the Tutorial and Didactic functions, but negatively associated with their use of the Control function. The mothers’ production of attuned mind-related comments bore no relation with children's expressive language. Similarities and differences with previous findings are discussed.

Maternal input influences language development in children with Down syndrome (DS) and typical development (TD). Telegraphic input, or simplified input violating English grammatical rules, is controversial in speech–language pathology, yet no research to date has investigated whether mothers of children with DS use telegraphic input. This study investigated the quality of linguistic input to children with DS compared to age-matched children with TD, and the relationship between maternal input and child language abilities. Mothers of children with DS simplified their input in multiple ways, by using a lower lexical diversity, shorter utterances, and more telegraphic input compared to mothers of children with TD. Telegraphic input was not significantly correlated with other aspects of maternal input or child language abilities. Since children with DS demonstrate specific deficits in grammatical compared to lexical abilities, future work should investigate the long-term influence of maternal telegraphic input on language development in children with DS.

Parents play an important role in creating home language environments that promote language development. A nonequivalent group design was used to evaluate the effectiveness of a community-based implementation of LENA Start™, a parent-training program aimed at increasing the quantity of adult words (AWC) and conversational turns (CT). Parent-child dyads participated in LENA Start™ (n = 39) or a generic parent education program (n = 17). Overall, attendance and engagement in the LENA StartTM program were high: 72% of participants met criteria to graduate from the program. Within-subject gains were positive for LENA Start™ families. Comparison families declined on these measures. However, both effects were non-significant. Between-group analyses revealed small to medium-sized effects favoring LENA Start™ and these were significant for child vocalizations (CV) and CT but not AWC. These results provide preliminary evidence that programs like LENA StartTM can be embedded in community-based settings to promote quality parent-child language interactions.

Judgements about the acceptability of anomalous and non-anomalous sentences were elicited from children between the ages of 2; 0 and 5; 0. Generally such judgements have been assumed to be a direct reflection of linguistic competence. Longitudinal study of individual children indicated that developmental changes in children's judgemental capacities were erratic, with sudden regressions in performance as well as sudden improvements. This was especially true of the youngest children, aged between 2; 0 and 3; 6. It appeared that, despite irregularity, certain general developmental patterns could be discerned. It is difficult to reconcile these findings with a view of sentence judgements which assumes that they directly represent linguistic competence. It is suggested that the most satisfactory explanation of the developmental data must rest on the assumption that not simply linguistic factors, but also cognitive/experiential factors are involved in sentence judgements.

Conventional implicatures are omnipresent in daily life communication but experimental research on this topic is sparse, especially research with children. The aim of this study was to investigate if eight- to twelve-year-old children spontaneously make the conventional implicature induced by but, so, and nevertheless in ‘p but q’ sentences. Additionally, the study aimed to shed light on the cognitive effort required for these inferences by measuring working memory (WM) capacity. Our results show that children do make these inferences to a certain extent, but are sensitive to the content of the arguments. We found a significant effect of sentence type, but did not observe any developmental effect, nor any effect of WM: a higher age or WM capacity does not result in more pragmatic inferences.

The interpretation of floating quantifiers in Japanese requires knowledge of hierarchical phrase structure. However, the input to children is insufficient or even misleading, as our analysis indicates. This presents an intriguing question on learnability: do children interpret floating quantifiers based on a structure-dependent rule which is not obvious in the input or do they employ a sentence comprehension strategy based on the available input? Two experiments examined four- to six-year-old Japanese-speaking children for their interpretations of floating quantifiers in SOV and OSV sentences. The results revealed that no child employed a comprehension strategy in terms of the linear ordering of constituents, and most five- and six-year-olds correctly interpreted floating quantifiers when word-order difficulty was reduced. These facts indicate that children's interpretation of floating quantifiers is structurally dependent on hierarchical phrase structure, suggesting that this knowledge is a part of children's grammar despite the insufficient input available to them.

Fillers appear during the early grammaticalization process, roughly between the one- or two-word phase and the earliest grammar, in a variety of languages. Peters accurately points out there have been theoretical and methodological difficulties when trying to integrate the filler phenomenon in language acquisition theory, probably because fillers do not fit neatly into linguistic categories, nor a structure of ‘modules’. Her note is a major contribution to the solution of those problems. She gives us a rich review that can guide any reader – specialised or naive – to deep, critical insights and to the relevant research literature. In addition to this valuable contribution, she points the way to future work. The very richness makes it difficult to add any interesting comments. So these remarks will be limited to complementary concepts and data.

This study examined five- to seven-year-olds' assumptions about the experiential connotation of ‘I know that's X’. In Experiment 1 children tried to identify which of a set of unfamiliar targets had a given name (X), and after they had chosen, we enquired either whether they KNEW their chosen item was (X) or whether they were SURE. Six- to seven-year-olds (N = 39) judged that they were sure more often than they judged that they knew, which suggests that although they experienced confidence that they had chosen correctly, they assumed it would be inappropriate to judge ‘know’, because this would imply an experiential basis, which was absent. Five- to six-year-olds (N = 36) did not discriminate between the two kinds of question. In Experiment 2, children could infer which item was a named unfamiliar cartoon character by ruling out familiar distractors. Six- to seven-year-olds (N = 35) judged that they knew they had picked the right one much more often than they judged that they knew their chosen picture was (target name). Again, five- to six-year-olds (N = 44) did not discriminate between the two kinds of question. This demonstrates powerfully that the older children held an experiential connotation of ‘I know that's X’, since they avoided such judgements even when they knew by inference they had chosen correctly.

Segmental variation in maternal speech to children changes over time. This study investigated variation in non-citation speech processes in a longitudinal, 26-hour corpus of maternal northern Australian English. Recordings were naturalistic parent–child interactions when children (N=4) were 1;6, 2;0, and 2;6. The mothers' speech was phonetically transcribed and analyzed. Based on previous sociophonetic research showing proportional changes in speech variants in maternal speech as children get older, it was predicted that deletion of word-initial /h/ and word-final /v/, processes common in non-citation speech, would increase over time. Instead results showed a non-linear change in deletion within a stable set of lexical items. Deletion proportionately increased between 1;6 and 2;0 and decreased between 2;0 and 2;6. Further analysis indicated increased deletion was not accounted for by changes in speech rate, which only marginally increased over time. Findings suggest mothers fine-tune differentially over time as children's receptive and productive language knowledge develops.

Acquisition of English grammatical morphology was examined in five internationally adopted (IA) children from China (aged 0;10–1;1 at adoption) during the first three years' exposure to English to determine whether acquisition patterns were characteristic of child second language (L2) learners or monolingual first language (L1) learners. Results from spontaneous and elicited speech showed that IA children acquired grammatical morphemes similarly to L1 learners; namely, (1) non-tense-marking morphemes were acquired earlier than tense-marking morphemes; (2) BE was acquired in synchrony with other tense-marking morphemes; and (3) a high percentage of omission errors and a low percentage of commission errors were observed.

Stoel-Gammon (this issue) states that ‘from birth to age 2 ; 6, the developing phonological system affects lexical acquisition to a greater degree than lexical factors affect phonological development’ (this issue). This conclusion is based on a wealth of data; however, the available data are somewhat limited in scope, focusing on rather holistic measures of the phonological and lexical systems (e.g. production accuracy, number of words known). Stoel-Gammon suggests a number of important avenues to pursue, but does not discuss a critical one that is emerging in the broader literature on word learning. Specifically, recent connectionist models and adult word learning research provide evidence that greater differentiation of the cognitive processes that underlie word learning yields new insights (Leach & Samuel, 2007). This approach may be fruitful for future investigations of the relationship between phonological and lexical development in young children.

This study is an attempt to trace the acquisition of consonant clusters by Telugu children. Phonemic inventories are given for each of the children for a clear picture of their acquisitional stage. It was found that reduction, substitution and assimilation played major roles in cluster acquisition. Co-occurrence restrictions and hierarchical application of the three phonological processes were noted. Results of this study are compared with similar works on Indian languages and English, and differences are pointed out.

The goal of this study was to investigate non-adjacent consonant sequence patterns in target words during the first-word period in infants learning American English. In the spontaneous speech of eighteen participants, target words with a Consonant–Vowel–Consonant (C1VC2) shape were analyzed. Target words were grouped into nine types, categorized by place of articulation (labial, coronal, dorsal) of initial and final consonants (e.g. mom, labial–labial; mat, labial–coronal; dog, coronal–dorsal). The results indicated that some consonant sequences occurred much more frequently than others in early target words. The two most frequent types were coronal–coronal (e.g. dad) and labial–coronal (e.g. mat). The least frequent type was dorsal–dorsal (e.g. cake). These patterns are consistent with phonotactic characteristics of English and infants' production capacities reported in previous studies. This study demonstrates that infants' expressive vocabularies reflect both ambient language characteristics and their own production capacities, at least for consonant sequences in C1VC2 word forms.

In The emergence of language, it is argued that much of what generative linguistics has characterized as ‘rules’ in fact can be derived from domain- general cognitive mechanisms. One example of this perspective is Bates & Goodman's contribution ‘On the emergence of grammar in the lexicon’, which Sabbagh & Gelman say offers ‘…a series of compelling arguments detailing how development and early acquisition shape the subsequent acquisition of new information.’ The thrust of the argument presented by Bates & Goodman is that there is no need to posit the existence of an independent grammar domain, because grammar can be reduced to the lexicon, which in Bates & Goodman's account, can be acquired using general purpose mechanisms. One of several major arguments in favour of this position presented by the authors is that grammar and vocabulary grow at the same rates in child speech. Thus, the authors argue that the development of the lexicon and grammar correlate because there is no grammar outside of the lexicon.

Perusing early issues of this Journal from nearly forty years ago, we find many topics on the contents lists that could appear in a current issue. But the resources available to contributors for addressing questions of interest have changed dramatically, not least in the public availability of data. Here we look briefly at two assets which have accrued to the field in the intervening decades, and at the contributions they make. CHILDES provides a level playing field on which debates about the import of language sample data, especially longitudinal data, can be played out. The MBCDI and its offspring encourage the collection of data from large samples of individuals and so promote the exploration of factors that may explain individual differences. Both have been major contributions to the field.

A case is reported of failure to supply negation in tag questions for a period of nearly two years. The duration of this error shows that it could not have been the result of limited processing capacity, and this provides reason to doubt this explanation for the similar case of children's failure to invert subject and auxiliary verb in wh-questions. It is argued that other cases which have been explained in terms of limited processing capacity are equally compatible with an explanation in terms of context-specific knowledge, which holds that a rule is simply not known for contexts other than those where it is expressed.

This paper investigates the comprehension of Relative Clauses (RCs) in 15 Mandarin children with suspected Specific Language Impairment (SLI) (aged between 4; 5 and 6; 0) and 29 typically developing (TD) controls. Results from a Character Picture Matching Task indicate that (i) the subject RC was better understood than the object RC in children with SLI, but there was no asymmetry in the comprehension of the two RCs in TD children; (ii) the performance of children with SLI was significantly worse than that of their TD peers; (iii) children with SLI were prone to committing thematic role reversal errors and middle errors. In order to overcome the shortcomings of previous accounts, we therefore put forward the Edge Feature Underspecification Hypothesis, which can not only explain the asymmetry of comprehension seen in children with SLI but also shed light on the nature of errors committed by them in the task.

The role of agent priority in event perception in word acquisition was investigated using 24 infants at the one-word stage of language production. Nonsense words were presented in narrations referring to agent, recipient or stationary nonsense puppet-actors in filmed events. The nonsense stimuli along with a sense word referring to a sense puppet were presented in a habituation series. Word acquisition was measured by the extent of response recovery to an incorrect pairing of a nonsense word with a sense referent, and by the number of infants accurately choosing named puppets. Both measures were significantly greater for puppets in agent roles than for other puppets. A speech modification condition (exaggerated intonation with repetition) held attention longer but did not facilitate acquisition.