Purpose: Traditional approaches to studying bilingual language development through bilingual-monolingual comparisons are deeply flawed. They are also insufficient as the evidence base for informing advice to bilingual parents regarding the optimal bilingual exposure strategy and for supporting the formulation of bilingual intervention approaches.…

Reviews recent theoretical and empirical literature regarding teachers' uses of the target (TL) and first languages (L1) in second and foreign language classrooms. Explores several issues related to teachers' use of the L1 and the TL in the classroom; exposure to TL input, student motivation, cognitive considerations, code switching, and…