This study investigated how various child-internal and child-external factors predict English L2 children's acquisition outcomes for vocabulary size and accuracy with verb morphology. The children who participated (N=169) were between 4;10 and 7;0 years old (mean = 5;10), had between 3 to 62 months of exposure to English (mean = 20 months), and were from newcomer families to Canada. Results showed that factors such as language aptitude (phonological short term memory and analytic reasoning), age, L1 typology, length of exposure to English, and richness of the child's English environment were significant predictors of variation in children's L2 outcomes. However, on balance, childinternal factors explained more of the variance in outcomes than child-external factors. Relevance of these findings for Usage-Based theory of language acquisition is discussed.Keywords: English language learners, child second language acquisition, individual differences, language aptitude, usage-based theory, l1 transfer 2. This questionnaire was developed by the author and her graduate students, with input from the Multicultural Health-Brokers Cooperative in Edmonton (www.mchb.org), for the purposes of conducting research with newcomer families from a variety of cultural/linguistic backgrounds. The ALEQ is available at www.chesl.ualberta.ca . 3.Re-running the model with the child-output variable did not result in this variable being selected in the stepwise regression procedures. 4.Re-doing the models with maternal education as a dichotomous variable did not result in this factor emerging as significant.

It has been claimed that children simultaneously acquiring two languages go through an initial stage when they are unable to differentiate between their two languages. Such claims have been based on the observation that at times virtually all bilingual children mix elements (e.g. lexical, morphological) from their two languages in the same utterance. That most, if not all, children acquiring two languages simultaneously mix linguistic elements in this way is widely documented. Although such code-mixing is not well understood or explained, there are a number of explanations unrelated to lack of language differentiation that may explain it. Moreover, while language differentiation is widely attested among bilingual children once functional categories emerge, usually during the third year, there is still some question as to how early in development differentiation is present. In this study, we examined language differentiation in five bilingual children prior to the emergence of functional categories (they ranged in age from 1;10 to 2;2 and in MLU from 1·23 to 2·08). They were observed with each parent separately and both together, on separate occasions. Our results indicate that while these children did code mix, they were clearly able to differentiate between their two languages. We also examine the possibility that the children's mixing is due to (a) their language dominance, and (b) their parents' rate of mixing. We could find no evidence that their mixing was due to parental input, but there was some evidence that language dominance played a role.

Recent research on pragmatic and syntactic development in bilingual 2-year-olds has shown that these children have differentiated language systems. However, it remains to be shown whether their grammars develop autonomously or interdependently from 2 years onward. The present study investigates the potential interference between the grammars of French-English bilingual children, aged 2–3 years. We examined their acquisition of functional categories, specifically the properties of INFL (finiteness and agreement) and negation, as these grammatical properties differ in both adult French and English and child French and English. Our results indicate that the bilingual children show no evidence of transfer, acceleration, or delay in acquisition, and support the hypothesis that their grammars are acquired autonomously. Some implications of these findings for the debate on continuity in the emergence of functional categories are discussed.

This study investigated whether crosslinguistic interference occurs in the domain of subject realization in Spanish in a bilingual acquisition context. We were also interested in exploring whether the source of the interference is due to child-internal crosslanguage contact between English and Spanish, as is commonly assumed, or due to the nature of the language input in a bilingual family, a factor which has not typically been considered in studies of crosslinguistic influence. The use of subjects in a null subject language like Spanish is a phenomenon linked to the pragmatics/syntax interface of the grammar, and thus, is a domain where crosslinguistic interference is predicted to be likely to occur in bilingual acquisition (Müller & Hulk, 2001). Using spontaneous language data available from CHILDES (www.childes.psy.cmu.edu), we examined the use of overt subjects in Spanish by two Spanish monolingual children (ages: 1;8–2;7 and 1;8–1;11) one Spanish–English bilingual child (age 1;9–2;6) and their parental interlocutors. We looked at the proportions of overt versus null subjects as well as the discourse-pragmatic contexts of overt subject use by the children in order to uncover bilingual/monolingual differences in the distributional properties and the functional determinants of subject realization. We also looked at identical variables in the speech of the children's parental interlocutors to investigate the potential influence of the input on the children's output. Our results suggest that the bilingual child showed patterns in her subject realizations in Spanish that could be interpreted as due to crosslinguistic effects from English; however, there is also evidence that these effects may have a source in the input, rather than resulting from internal crosslanguage contact. While our data do not permit us to distinguish conclusively between these two possible sources, they indicate that future research on crosslinguistic influence in bilingual acquisition should take input into account.

The English second language development of 19 children (mean age at outset = 5 years, 4 months) from various first language backgrounds was examined every 6 months for 2 years, using spontaneous language sampling, parental questionnaires, and a standardized receptive vocabulary test. Results showed that the children's mean mental age equivalency and standard scores on the Peabody Picture Vocabulary Test-Third Edition nearly met native-speaker expectations after an average of 34 months of exposure to English, a faster rate of development than has been reported in some other research. Children displayed the phenomenon of general all-purpose verbs through overextension of the semantically flexible verb do, an indicator of having to stretch their lexical resources for the communicative context. Regarding sources of individual differences, older age of second language onset and higher levels of mother's education were associated with faster growth in children's English lexical development, and nonverbal intelligence showed some limited influence on vocabulary outcomes; however, English use in the home had no consistent effects on vocabulary development.