Abstract
Despite the fact that Applied Linguistics has achieved invaluable results in many areas of language as in the areas of language change, language acquisition, and language universals , its research studies still neglect the question of whether foreign language learning (L2) has any influences on the mother tongue (L1) or not. In this paper, the author reviews some Studies to shed light on the problem of transfer, and to show that most of them are merely concerned with the study of the influence of the L1 on L2 , and do not have any attempts to see whether the L2 also has its impact on the L1. Hence, the author prefers to indicate to these studies as 'one–sided' 'one–eyed' Studies. The author hopes to pave the road for those researchers who still have the interest in discovering whether L2-learning has any influences on the L1