The study deals with the effect of native tongue in SLA(second language acquisition). As is well-known, learning a second language is a complicated process, which is affected by a series of interrelated factors. Among these factors, the native or first language of a second language learner also plays an important role. Owning to this, the study of the role of L1(the first language) in SLA is inevitable. Many studies have been carried out in this field and the results are inconclusive. The study aims at making an overview of the various conclusions of the preceded studies and each previous assertion or conclusion is supported by its corresponding empirical studies. Equally speaking, the paper is going to solve the problem that what is the exact role of native language in SLA and the personal opinion of the researcher is provided as a conclusion of this study.
