This study investigated the effects of family composition and properties of children's dual language exposure on bilingual first language acquisition. Mothers of 29 toddlers (13 boys and 16 girls, M age = 25.66 months, SD = .44) kept a language diary, providing measures of the amount, the contexts, and the persons with whom the children experienced English and Spanish. Measures of the children's vocabulary balance were obtained from English and Spanish language inventories. Results showed that only children with two native Spanish-speaking parents had larger Spanish than English vocabularies and experienced more hours of Spanish-only exposure and Spanish-only conversational contexts. Analysis of covariance demonstrated that the effect of family composition on vocabulary balance was completely mediated by the balance of English and Spanish in the children's language exposure. There was no evidence of a unique effect of experiencing Spanish-only conversational contexts or partners on children's acquisition of Spanish. / by Silvia Place. / Thesis (M.A.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

The current study addressed several questions about the use of language intermingling in child-directed speech and its influence on children's English and Spanish language acquisition on children's language code-switching, Participants were 65 children (Mean age=30.93 months, SD=0.44, 28 boys and 37 girls) who had been exposed to English and Spanish from birth and for whom at least one parent was a native Spanish speaker.... Measures of the children's lexical, grammatical, receptive, and productive language development in English and in Spanish were collected concurrently.... Consistent with sociolinguistic theories that propose that language separation is necessary for heritage language maintenance, children who were exposed to more language intermingling were more English-dominant. Both sensitivity to the language context and children's language dominance were related to children's production of mixed utterances. Children code-switched more when speaking in their less proficient language and when in the context of minority language use. / by Silvia Place. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.