Bilingual Language Acquisition:The Relation of First and Second Lamguage in The Development of Bilingual Proficiency

Bilingualism is becoming increasingly common because of more frequent immigration and the new teaching concept adopted by many schools.One becomes bilingual either by acquiring two languages at the same time in childhood or by learning a second language sometime after acquiring their first language.To know more about bilingualism is of great importance,particularly to language teachers and learners.This article tries to analyze a bilingual's language development on the basis of existing researches by some great linguists and tries to find out how to realize the positive language transfer in English teaching and learning through the interaction between two languages.