How early can we efficiently start teaching a foreign language?

The appropriateness of early childhood foreign language education is occasionally a debatable subject among parents, educators, public education administrators and policymakers. A large body of research has been done on this subject and conclusions sometimes appear contradictory. This article first reviews briefly the importance of learning a foreign language, and the advantages of bilingualism. Second, it compiles empirical evidence that concerns early foreign language education of children living in a native language speaking environment and suggests answers to questions regarding the developmentally appropriate timing to start providing foreign language education services.