ABSTRACT
I n the United States, an increasing number of children learn language in a bilingualenvironment. Simultaneous bilinguals are those who are exposed to two languagesfrom birth, or from a very early age (typically before 2 years). Sequential bilinguals learn a second language after they have mastered the first. The majority of these bilingual children are known as early “sequential” bilinguals-learning a home language first-then learning English at the time of initial formal schooling (i.e., preschool or kindergarten). They typically learn a second language after age 2, before mastering their home language. When sequential bilinguals are in the early phase of learning language, it is difficult to differentiate language impairment (LI) from language differences. Until very recently, there have been few systematic studies of LI in bilingual children. Now there is a small, growing database of research that informs practice in this area. In this chapter, we first review some of the prevailing theories about bilingual language acquisition; next we discuss the social factors influencing bilingualism in the United States; then, studies of LI in bilinguals are reviewed with particular attention to similarities and differences in markers of impairment; finally, we discuss current trends and practices in language assessment of bilinguals. For these two latter points we draw on our own research examining language acquisition and LI in Spanish-English bilinguals-one of the largest bilingual populations in the United States.
