ABSTRACT
Some global estimates of the number of bilingual children are as high as 50%. This chapter reviews the extant literature of bilingual lexical acquisition in the first years of life. The earliest "assessments" of bilingual children's vocabularies were diary studies published by linguists concerning their own bilingual children. Bilinguals' potentially unequal vocabularies across their languages and the fact that translation equivalents usually comprise less than half of their vocabulary have ramifications for vocabulary assessment. The majority of bilingual work demonstrates that young bilingual children have significantly lower vocabularies in their non-dominant language when compared to monolinguals of that language. The extant literature on early bilingual word learning and recognition primarily focuses on the former over the latter. Word recognition skills may not fundamentally differ across young bilinguals and monolinguals, but may be subject to the intricacies of dual-language input. Research on bilingual lexical acquisition reveals striking similarities between bilingual and monolingual infants and toddlers.
