What Clinicians Need to Know about Bilingual Development.

Basic research on bilingual development suggests several conclusions that can inform clinical practice with children from bilingual environments. They include the following: (1) Dual language input does not confuse children. (2) It is not necessary for the two languages to be kept separate in children's experience to avoid confusion. (3) Learning two languages takes longer than learning one; on average, bilingual children lag behind monolingual children in single language comparisons. (4) A dominant language is not equivalent to an only language. (5) A measure of total vocabulary provides the best indicator of young bilingual children's language learning capacity. (6) Bilingual children can have different strengths in each language. (7) The quantity and quality of bilingual children's input in each language influence their rates of development in each language. (8) Immigrant parents should not be discouraged from speaking their native language to their children. (9) Bilingual environments vary enormously in the support they provide for each language, with the result that bilingual children vary enormously in their dual language skills. Empirical findings in support of each conclusion are presented.