Special section: Language development in multilingual environments ‘‘ ¿ Co ´ mo estas?’’ ‘‘I’m good.’’ Conversational code-switching is related to profiles of expressive and receptive proficiency in Spanish-English bilingual toddlers Krystal M. Ribot and Erika Hoff Abstract Relations between bilingual children’s patterns of conversational code-switching (responding to one language with another), the balance of their dual language input, and their expressive and receptive proficiency in two languages were examined in 115 2½-year-old simultaneous Spanish-English bilinguals in the U.S. Children were more likely to code-switch in response to Spanish than English. Children’s expressive vocabulary scores were higher in English than in Spanish, while their English and Spanish receptive language scores were not different. Analyses of subgroups of children with different but consistent patterns of code-switching confirmed that children who code-switched to English showed greater English skills, specifically in the expressive domain. Children who did not code-switch were more balanced bilin- guals in both expressive and receptive skills. Children with other code-switching patterns showed still different profiles of dual language expressive and receptive proficiency. These findings reveal that some, but not all, bilingual children show different profiles of expressive and receptive skill in their two languages and that these proficiency profiles are related to their language choices in conversation. Keywords bilingual profiles, code-switching, expressive vocabulary, language choice, language proficiency, receptive language Parents of bilingual preschool children are often puzzled by what appears to be their children’s choice to speak only one language in everyday interaction, although they understand two. Researchers have also described this phenomenon. For example, De Houwer (2007) cites several accounts of children in bilingual environments who speak only one language, ‘‘even with a parent who speaks another language to them’’ (p. 411), and Hurtado and Vega (2004) describe parents and children speaking to each other and understand- ing each other even though ‘‘the children may be speaking mostly in English, and the parents mostly in Spanish’’ (p. 148). When children respond to one language using another, it is one form of code-switching. Code-switching is a ubiquitous feature of speech in bilingual communities, and code-switching by young bilingual children has been well documented (Genesee & Nicola- dis, 2007). The question of when and why children code-switch is an active area of investigation. In this study, we focus on conver- sational code-switching in very young bilinguals. We ask first whether 2½-year-old Spanish-English bilingual children show asym- metries in their conversational code-switching—more frequently switching in one direction than the other, and we ask what might underlie any asymmetries observed. Several candidate, but not mutually exclusive, explanations of asymmetries in code-switching can be found in the literature. One possibility is that asymmetries in language choice reflect differences between the languages in societal prestige or dominance. In the U.S., English is the language of the dominant culture and the more presti- gious language (Eilers, Pearson, & Cobo-Lewis, 2006). Greene, Pen ˜a, & Bedore (2012) found that American Spanish-English bilingual 5-year-olds were more likely to switch to English when being tested in Spanish than they were to switch to Spanish when being tested in English, regardless of which language was their stron- ger language. Gutie ´rrez-Clellen and colleagues found that the examiner-elicited speech of 5-year-old Spanish-English bilingual children tested at their preschool Head Start sites more frequently contained code-switched utterances when elicitation was in Spanish than when it was in English (Gutie ´rrez-Clellen, Simon-Cereijido, & Leone, 2009). Gutie ´rrez-Clellen et al. (2009) suggested the children were aware that English was the language prescribed by the majority culture in the school environment. Another possible explanation of asymmetries in code-switching is that children’s choice of languages for speaking reflects what they hear in their immediate environments. In Hurtado and Vega’s (2004) example, the parents who addressed their children in Span- ish likely heard more Spanish than English in their daily lives, while the children who answered their parents in English likely heard more English than Spanish in theirs. Similarly, Pearson, Ferna ´ndez, Lewedeg, and Oller (1997) reported anecdotally that the bilingual children in their study who received less than 20% of their input in one language were reluctant to interact in that language, Florida Atlantic University, USA Corresponding author: Krystal Marie Ribot, Florida Atlantic University, Davie, FL, USA. Email: klago3@fau.edu International Journal of Behavioral Development 2014, Vol. 38(4) 333–341 ª The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0165025414533225 ijbd.sagepub.com