This longitudinal case study documents the emergence of bilingualism in a young monolingual Mandarin boy on the basis of an acoustic analysis of his vowel productions recorded via a picture-naming task over 20 months following his enrollment in an all-English (L2) preschool at the age of 3;7. The study examined (1) his initial L2 vowel space, (2) the process of L1-L2 separation, and (3) his L1 vowel system in relation to L2. The child initially utilized his L1 base in building the L2 vowel system. The L1-L2 separation started from a drastic restructuring of his working vowel space to create maximal contrast between the two languages. Meanwhile, L1 developmental processes and influence of L2 on L1 were also in effect. The developmental profile of this child uncovered strategies sequential bilingual children may use to restructure their phonetic space and construct a new system of contrasts in L2.

Fast mapping weaknesses in children with specific language impairment (SLI) may be explained by differences in disambiguation, mapping an unknown word to an unnamed object. The impact of language ability and linguistic stimulus on disambiguation was investigated. Sixteen children with SLI (8 preschool, 8 school-age) and sixteen typically developing age-matched children selected referents given familiar and unfamiliar object pairs in three ambiguous conditions: phonologically distinct word (PD), phonologically similar word (PS), no word (NW). Preschoolers with SLI did not disambiguate, unlike typically developing age-matched participants, who consistently selected unfamiliar objects given PD. School-age children with SLI disambiguated given PD. Delays in disambiguation for young children with SLI suggest limitations in processes that facilitate word learning for typically developing children. School-age children with SLI consistently selected familiar objects for PS, unlike typically developing children, suggesting differences in phonological activation for word learning.

The acquisition of systematic patterns and exceptions in different languages can be readily examined using the causative construction. Persian allows four types of causative structures, including one productive multiword structure (i.e. the light verb construction). In this study, we examine the development of all four structures in Persian child speech between the ages of 1;11 and 6;7, in correspondence with their caregivers’ speech. We define developmental stages based on dendrograms derived from variability clustering (Gries & Stoll, 2009). These stages are further substantiated by qualitative data, including overgeneralization errors and alternating structures. We find that Persian-speaking children learn to exploit two (i.e. lexical and light verb construction causatives) of the four constructions. They go from relying on lexical causatives to forming progressively constrained templates for the more complex light verb construction. This first study of the development of Persian causatives supports a usage-based account of verb-by-verb learning in child language development.

Young children's first attempts at CVC words are often realized with the final consonant being heavily aspirated or followed by an epenthetic vowel (e.g. cat /kæt/ realized as [kæth] or [kætə]). This has led some to propose that young children represent word-final (coda) consonants as an onset-nucleus sequence (CV.Cv) (e.g. Goad & Brannen, 2003), raising questions about the syllabic status of the final consonant. To address this issue, we conducted an acoustic analysis of a child's early production of CVC, CVCh, and CVCV words between the ages of 1;3 and 1;5. Aside from aspiration, the results showed that there were no significant acoustic differences between the CVC and CVCh forms. In contrast, there were systematic acoustic differences in C2 closure duration between the CVC/CVCh and CVCV target words, suggesting that at least some children learning English have early coda representations for monosyllabic CVC words, whether heavily aspirated or not.

Cross-linguistic influence (CLI) refers to the linguistic influence of one of a bilingual's languages while processing the other. Researchers have debated whether CLI is better explained by the structure of bilinguals' two languages or by a combination of processing demands and structure. In this study, we test if Welsh–English bilingual children manifest CLI when producing adjectival constructions. Welsh adjectives typically appear postnominally, English adjectives typically appear prenominally. Since these structures do not overlap, there may be no CLI. If, however, CLI is a result of competition between languages, children's adjectival constructions may be reversed in both languages. We elicited adjectival constructions from Welsh–English bilingual children and English monolingual children between three and six years of age. The bilingual children produced more reversals than monolinguals and equivalent rates of reversals in both languages. In other words, the results support an interpretation of CLI resulting, at least in part, from processing demands.

The present study compared the performance of twenty-seven French-speaking internationally adopted (IA) children from China to that of twenty-seven monolingual non-adopted French-speaking children (CTL) matched for age, gender, and socioeconomic status on a Clitic Elicitation task. The IA children omitted significantly more accusative object clitics and made significantly more agreement errors using clitics than the CTL children. No other significant differences were found between the groups. The findings suggest that the adoptees may experience difficulties in morphosyntactic development possibly as a result of their delayed exposure to the adopted language.

We investigated whether children at the ages of two and three years understand that a speaker's use of the definite article specifies a referent that is in common ground between speaker and listener. An experimenter and a child engaged in joint actions in which the experimenter chose one of three similar objects of the same category to perform an action. In subsequent interactions children were asked to get ‘the X’ or ‘a X’. When children were instructed with the definite article they chose the shared object significantly more often than when they were instructed with the indefinite article in which case children's choice was at chance. The findings show that in their third year children use shared experiences to interpret the speaker's communicative intention underlying her referential choice. The results are discussed with respect to children's representation of linguistic categories and the role of joint action for establishing common ground.

This study compares parental pause and utterance duration in conversations with Swedish speaking children at age 1;6 who have either a large, typical, or small expressive vocabulary, as measured by the Swedish version of the McArthur-Bates CDI. The adjustments that parents do when they speak to children are similar across all three vocabulary groups; they use longer utterances than when speaking to adults, and respond faster to children than they do to other adults. However, overall pause duration varies with the vocabulary size of the children, and as a result durational aspects of the language environment to which the children are exposed differ between groups. Parents of children in the large vocabulary size group respond faster to child utterances than do parents of children in the typical vocabulary size group, who in turn respond faster to child utterances than do parents of children in the small vocabulary size group.

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.

A fundamental question in language acquisition research is whether young children have abstract grammatical representations. We tested this question experimentally. French-learning 30-month-olds were first taught novel word–object pairs in the context of a gender-marked determiner (e.g., unMASCravole ‘a ravole’). Test trials presented the objects side-by-side while one of them was named in new phrases containing other determiners and an adjective (e.g., leMASCjoli ravoleMASC ‘the pretty ravole’). The gender agreement between the new determiner and the non-adjacent noun was manipulated in different test trials (e.g., leMASC__ravoleMASC; *laFEM__ravoleMASC). We found that online comprehension of the named target was facilitated in gender-matched trials but impeded in gender-mismatched trials. That is, children assigned the determiner genders to the novel nouns during word learning. They then processed the non-adjacent gender agreement between the two categories (Det, Noun) during test. The results demonstrate abstract featural representation and grammatical productivity in young children.

In two sentence repetition experiments, we investigated whether four- and five-year-olds master distinct representations for intransitive verb classes by testing two syntactic analyses of unaccusatives (Burzio, 1986; Belletti, 1988). Under the assumption that, with unaccusatives, the partitive case of the postverbal argument is realized only on indefinites (Belletti, 1988), we tested whether children used indefiniteness as a feature to assign the partitive case to the verb's argument. In the sentences, we manipulated whether the subject preceded or followed the (unaccusative or unergative) verb and whether the subject was expressed by means of a definite or indefinite NP. With unaccusatives, children tended to place the subject in the postverbal position when the subject NP was indefinite, whereas, when the sentence presented a definite postverbal subject, children preferred to place the definite subject in the preverbal position. Definiteness exerted an effect only with unaccusatives, suggesting that children treated unergatives and unaccusatives differently.

The gender and number of a direct object clitic pronoun are based on the gender and number of the noun to which it refers. Grammatical gender is an intrinsic property of the lexical item that is independent from the natural sex of referents, whereas number is a non-intrinsic feature of nouns based on the conceptual level of quantity. The aim of this paper is to investigate children's ability in matching Italian direct object clitic pronouns to an inanimate visual referent on the basis of number or gender information. The dependent variables are accuracy and response time. A total of sixty-nine children aged from 4;6 to 7;5 participated. The results show that children are more accurate and faster in selecting the referent when they use number information compared to the condition in which this matching operation is led by gender.

Young children typically do not use order-of-mention to resolve ambiguous pronouns, but may do so if given additional cues, such as gestures. Additionally, this ability to utilize gestures may be enhanced in bilingual children, who may be more sensitive to such cues due to their unique language experience. We asked monolingual and bilingual four-year-olds and adults to determine referents of ambiguous pronouns given order-of-mention and co-referential localizing gestures. Results showed that bilingual children, like adults, but not monolingual children, used order-of-mention with gestures to resolve ambiguous pronouns. This highlights a wider implication of bilingualism for socio-cognitive development in children.

This study examines whether lexical repetition, syntactic skills, and working memory (WM) affect children's syntactic-priming behavior, i.e. their tendency to adopt previously encountered syntactic structures. Children with Specific Language Impairment (SLI) and typically developing (TD) children were primed with prenominal (e.g. the yellow cup) or relative clause (RC; e.g. the cup that is yellow) structures with or without lexical overlap and performed additional tests of productive syntactic skills and WM capacity. Results revealed a reliable syntactic-priming effect without lexical boost in both groups: SLI and TD children produced more RCs following RC primes than following prenominal primes. Grammaticality requirements influenced RC productions in that SLI children produced fewer grammatical RCs than TD children. Of the additional measures, WM positively affected how frequently children produced dispreferred RC structures, but productive syntactic skills had no effect. The results support an implicit-learning account of syntactic priming and emphasize the importance of WM in syntactic priming tasks.