The present study examined the number-specific parental language input to Mandarin- and English-speaking preschool-aged children. Mandarin and English transcripts from the CHILDES database were examined for amount of numeric speech, specific types of numeric speech and syntactic frames in which numeric speech appeared. The results showed that Mandarin-speaking parents talked about number more frequently than English-speaking parents. Further, the ways in which parents talked about number terms in the two languages was more supportive of a cardinal interpretation in Mandarin than in English. We discuss these results in terms of their implications for numerical understanding and later mathematical performance.

Twenty-four infants at 1 ; 1 and their mothers were videotaped for 18 minutes while playing. Infants' pointing, reaching and object-extending gestures were coded in three communicative intent contexts: proto-declarative, or commenting; proto-imperative, or requesting; and ambiguous. Mothers' responses to infants' gestures were coded as object labels, action labels, internal state labels and non-labeling utterances. Infants most often pointed in the proto-declarative and used object extensions in the proto-imperative context. Infants produced pointing and reaching equivalently in the ambiguous context. Mothers' responses included object labels more often in response to points than object extensions. In contrast, mothers provided action labels most often in response to object extensions. Mothers produced large proportions of internal state labels, although the type varied by gesture. Results suggest mothers' labels following infants' gestures may serve as a mechanism for vocabulary acquisition and internal state understanding.

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.

Bilingual and monolingual children's (mean age=4;10) elicited production of the past tense in both English and French was examined in order to test predictions from Usage-Based theory regarding the sensitivity of children's acquisition rates to input factors such as variation in exposure time and the type/token frequency of morphosyntactic structures. Both bilingual and monolingual children were less accurate with irregular than regular past tense forms in both languages. Bilingual children, as a group, were less accurate than monolinguals with the English regular and irregular past tense, and with the French irregular past tense, but not with the French regular past tense. However, bilingual children were as accurate as monolinguals with the past tense in their language of greater exposure, except for English irregular verbs. It is argued that these results support the view that children's acquisition rates are sensitive to input factors, but with some qualifications.

In many learning situations, we need to determine to which cues to attend, particularly in cases when these cues conflict. These conflicts appear often in English orthography. In two experiments, we asked children to spell two-syllable words that varied on two dimensions: morphological and orthographic structure. In one set of these words, the two sources of information conflicted. Results of Experiment 1 suggest that seven- to nine-year-old children are sensitive to both orthographic and morphological dimensions of words, and that this dual sensitivity sometimes leads to correct spelling and sometimes to incorrect spelling. Results of Experiment 2 suggest that orthographic information dominates young (six-year-old) children's spelling, at least in a case when there is a strong orthographic regularity. Taken together, these experiments suggest that children are sensitive to the multiple dimensions of regularity in English orthography and that this sensitivity can lead to mistakes.

This study provides experimental evidence for preschool children's competence in basic information structure, with particular attention to the notions of topic and focus. It investigates their mastery of structural and definiteness distinctions to encode the information status of discourse referents, and seeks to distinguish linguistic competence from cognitive development as the source for children's ‘errors’. Evidence comes from a story-telling experiment performed on 45 children acquiring French (between the ages of 2 ; 6·22 and 5 ; 6·15). The article demonstrates continuity between the child and adult systems of basic discourse representation. It further argues that children's definiteness errors are not due to a lack of knowledge of the adult rules of information encoding. Rather, such errors stem from cognitive limitations and from assuming a wider common ground than adults would.

This study examined how four- to five-year-olds and seven- to eight-year-olds used intonation (accent placement and accent type) to encode topic and focus in Dutch. Naturally spoken declarative sentences with either sentence-initial topic and sentence-final focus or sentence-initial focus and sentence-final topic were elicited via a picture-matching game. Results showed that the four- to five-year-olds were adult-like in topic-marking, but were not yet fully adult-like in focus-marking, in particular, in the use of accent type in sentence-final focus (i.e. showing no preference for H*L). Between age five and seven, the use of accent type was further developed. In contrast to the four- to five-year-olds, the seven- to eight-year-olds showed a preference for H*L in sentence-final focus. Furthermore, they used accent type to distinguish sentence-initial focus from sentence-initial topic in addition to phonetic cues.

Within the subfields of linguistics, traditional approaches tend to examine different phenomena in isolation. As Stoel-Gammon (this issue) correctly states, there is little interaction between the subfields. However, for a more comprehensive understanding of language acquisition in general and, more specifically, lexical and phonological development, we must consider relations between multiple subfields. That is, by examining the interactions between these subfields, a greater understanding of lexical and phonological development can emerge. For instance, the interaction between phonology, syntax and semantics is demonstrated in recent work looking at how phonological patterns can provide a basis for inferring a word's lexical category (such as nouns and verbs) (Christiansen, Onnis & Hockema, 2009; Lany & Saffran, 2010).

An auditory sentence comprehension task investigated the extent to which the integration of contextual and structural cues was mediated by verbal memory span with 32 English-speaking six- to eight-year-old children. Spoken relative clause sentences were accompanied by visual context pictures which fully (depicting the actions described within the relative clause) or partially (depicting several referents) met the pragmatic assumptions of relativization. Comprehension of the main and relative clauses of centre-embedded and right-branching structures was compared for each context. Pragmatically appropriate contexts exerted a positive effect on relative clause comprehension, but children with higher memory spans demonstrated a further benefit for main clauses. Comprehension for centre-embedded main clauses was found to be very poor, independently of either context or memory span. The results suggest that children have access to adult-like linguistic processing mechanisms, and that sensitivity to extralinguistic cues is evident in young children and develops as cognitive capacity increases.

In the present study, the development of semantic categorization and its relationship with reading was investigated across Dutch primary grade students. Three Exemplar-level tasks (Experiment 1) and two Superordinate-level tasks (Experiment 2) with different types of distracters (phonological, semantic and perceptual) were administered to assess semantic categorization skills. Reading was measured with a standardized word-reading test. Results of both experiments demonstrated that children in the higher grades had shorter reaction times and fewer errors than children in the lower grades. Reading skill, however, was not related to semantic categorization performance. Moreover, neither grade level nor reading skill was related to the effect of distracter type on error percentages. Based on the results of this study, we suggest a substantial development of semantic categorization skills over time, and reject the notion that Dutch poor readers have less advanced semantic categorization skills than typical readers.

Object relative clauses have traditionally been thought to be more difficult than subject relative clauses in child English. However, recent studies as well as Japanese data show contradictory results. This study disclosed preschool children's superior performance on object relative clauses in Japanese; however, this dominance disappeared for the children who could use both the nominative and accusative case markers as cues for the comprehension of single-argument sentences. Assuming a filler–gap dependency for the relative clause formation, we suggest that there is no difference in the difficulty between subject and object relative clauses in the grammar of Japanese-speaking children.

This study investigated vocabulary size and vocabulary composition in Greek children aged 1 ; 6 to 2 ; 11 using a Greek adaptation of Rescorla's Language Development Survey (LDS; Rescorla, 1989). Participants were 273 toddlers coming from monolingual Greek-speaking families. Greek LDS data were compared with US LDS data obtained from the instrument's normative sample (Achenbach & Rescorla, 2000). Vocabulary size increased markedly with age, but Greek toddlers appeared to get off to a slower start in early word learning than US children. The correlation between percentage word use scores in Greek and US samples was moderate in size, indicating considerable overlap but some differences. Common nouns were the largest category among the fifty most frequent words in both samples. Numbers of adjectives and verbs were comparable across languages, but people and closed-class words were more numerous in the Greek sample. Finally, Greek late talkers showed similar patterns of vocabulary composition to those observed in typically developing Greek children.

In her interesting article, Stoel-Gammon (this issue) reviews studies concerning the interactions between lexical and phonological development. While the focus of the review is on vocabulary production from children acquiring American English, she also suggests that cross-linguistic research be undertaken to examine how universal and language-specific properties affect the interaction between lexical and phonological acquisition. In this regard, Stoel-Gammon referred to the study of Bleses et al. (2008) who found differences in receptive vocabulary development across languages, based on norming studies for the Communicative Development Inventories (Fenson, Marchman, Thal, Dale, Reznick & Bates, 2007). Bleses et al. showed that Danish children were slower in the early comprehension of words (and phrases). It was hypothesized that the phonetic structure of Danish may account for the difference in receptive vocabulary skills in this population (Bleses & Basbøll, 2004).

Error patterns in children's phonological development are often described as simplifying processes that can interact with one another with different consequences. Some interactions limit the applicability of an error pattern, and others extend it to more words. Theories predict that error patterns interact to their full potential. While specific interactions have been documented for certain pairs of processes, no developmental study has shown that the range of typologically predicted interactions occurs for those processes. To determine whether this anomaly is an accidental gap or a systematic peculiarity of particular error patterns, two commonly occurring processes were considered, namely Deaffrication and Consonant Harmony. Results are reported from a cross-sectional and longitudinal study of twelve children (age 3 ; 0–5 ; 0) with functional phonological delays. Three interaction types were attested to varying degrees. The longitudinal results further instantiated the typology and revealed a characteristic trajectory of change. Implications of these findings are explored.

Children look longer at a familiar object when presented with either correct pronunciations or small mispronunciations of consonants in the object's label, but not following larger mispronunciations. The current article examines whether children display a similar graded sensitivity to different degrees of mispronunciations of the vowels in familiar words, by testing children's sensitivity to 1-feature, 2-feature and 3-feature mispronunciations of the vowels of familiar labels: Children aged 1 ; 6 did not show a graded sensitivity to vowel mispronunciations, even when the trial length was increased to allow them more time to form a response. Two-year-olds displayed a robust sensitivity to increases in vowel mispronunciation size, differentiating between small and large mispronunciations. While this suggests that early lexical representations contain information about the features contributing to vocalic identity, we present evidence that this graded sensitivity is better explained by the acoustic characteristics of the different mispronunciation types presented to children.

By their second birthday, children are beginning to map meaning to form with relative ease. One challenge for these developing abilities is separating information relevant to word identity (i.e. phonemic information) from irrelevant information (e.g. voice and foreign accent). Nevertheless, little is known about toddlers' abilities to ignore irrelevant phonetic detail when faced with the demanding task of word learning. In an experiment with English-learning toddlers, we examined the impact of foreign accent on word learning. Findings revealed that while toddlers aged 2 ; 6 successfully generalized newly learned words spoken by a Spanish-accented speaker and a native English speaker, success of those aged 2 ; 0 was restricted. Specifically, toddlers aged 2 ; 0 failed to generalize words when trained by the native English speaker and tested by the Spanish-accented speaker. Data suggest that exposure to foreign accent in training may promote generalization of newly learned forms. These findings are considered in the context of developmental changes in early word representations.

Speakers often anticipate how recipients will interpret their utterances. If they wish some other, less obvious interpretation, they may ‘mark’ their utterance (e.g. with special intonations or facial expressions). We investigated whether two- and three-year-olds recognize when adults mark a non-verbal communicative act – in this case a pointing gesture – as special, and so search for a not-so-obvious referent. We set up the context of cleaning up and then pointed to an object. Three-year-olds inferred that the adult intended the pointing gesture to indicate that object, and so cleaned it up. However, when the adult marked her pointing gesture (with exaggerated facial expression) they took the object's hidden contents or a hidden aspect of it as the intended referent. Two-year-olds' appreciation of such marking was less clear-cut. These results demonstrate that markedness is not just a linguistic phenomenon, but rather something concerning the pragmatics of intentional communication more generally.

This paper sets out to show how facilitation between different clause structures operates over time in syntax acquisition. The phenomenon of facilitation within given structures has been widely documented, yet inter-structure facilitation has rarely been reported so far. Our findings are based on the naturalistic production corpora of six toddlers learning Hebrew as their first language. We use regression analysis, a method that has not been used to study this phenomenon. We find that the proportion of errors among the earliest produced clauses in a structure is related to the degree of acceleration of that structure's learning curve; that with the accretion of structures the proportion of errors among the first clauses of new structures declines, as does the acceleration of their learning curves. We interpret our findings as showing that learning new syntactic structures is made easier, or facilitated, by previously acquired ones.

The goal of this study was to examine the influence of part-word phonotactic probability/neighborhood density on word learning by preschool children with normal vocabularies that varied in size. Ninety-eight children (age 2 ; 11–6 ; 0) were taught consonant-vowel-consonant (CVC) nonwords orthogonally varying in the probability/density of the CV (i.e. body) and VC (i.e. rhyme). Learning was measured via picture naming. Children with the lowest expressive vocabulary scores showed no effect of either CV or VC probability/density, although floor effects could not be ruled out. In contrast, children with low or high expressive vocabulary scores demonstrated sensitivity to part-word probability/density with the nature of the effect varying by group. Children with the highest expressive vocabulary scores displayed yet a third pattern of part-word probability/density effects. Taken together, word learning by preschool children was influenced by part-word probability/density but the nature of this influence appeared to depend on the size of the lexicon.

Stoel-Gammon (this issue) provides a welcome addition to the phonological acquisition literature, bringing together insights from long-standing and more recent research to address the relationship between the developing phonological system and the developing lexicon. A growing literature on children's early use of words across languages and phonological contexts provides additional insight into the nature of the interactions between phonological and lexical development, suggesting that learners' knowledge and connection of the two may develop much earlier than often thought. This commentary highlights some of these exciting results from recent cross-linguistic research on development between the ages of 1 and 3.