The purpose of this study is to explore the current state of using a student’s mother tongue (L1) in a foreign language classroom where students are learning another language (L2). More specifically, the study approaches the subject of code switching with two questions: is the inclusion of the L1 in an L2 classroom beneficial or detrimental to student development in language proficiency and, if it is found to be beneficial, is it most effective for semantic language, vocabulary building, or both. The results indicate that overall the benefits of using code switching seem to be greater than possible difficulties that may arise in the classroom from its use. Also, code switching seems to be used most frequently and effectively for vocabulary building, but is often confused for simple borrowing. It is further recommended that a clear definition for code switching is specified that is shared throughout the research on the subject.