Investigating the teachers' use of L1 in EFL classes

English has been acknowledged to be the global language of business, trade, science, and academic studies. In the development of English language competence, there has been an ongoing debate among the scholars on whether the mother tongue (L1) or the target language (L2) should be used in the instructional process. Two lines of thoughts have dominated on this debate. According to the proponents of monolingualism or "the English-only policy", the use of L1 prevents learners from acquiring the L2; therefore, L1 should be abolished from English as a second/foreign (ESL/EFL) classroom activities. On the other hand, the opponents of the English-only policy have claimed that L1 can be employed as a beneficial tool in learning the target language. This study aims to investigate Turkish EFL teachers' perspectives on the use of L1 in foreign language classrooms, functions that the teachers' use of L1 serves in English classes, and the amount of L1 use, as perceived by English teachers. Mixed method research design was adopted in order to seek answers to the research questions, and two research instruments have been used to collect data. Data was collected from 43 English teachers working in the Private Beyza Boğaziçi School, Private İsmet Karaokur Simya College and Doğa College located in a province in Turkey, using purposeful sampling. In addition, six volunteering teachers were interviewed. The Use of L1 Questionnaire, comprising three parts, was used to gather both quantitative and qualitative data, and semi-structured interviews were used to obtain qualitative data. Quantitative data from the closed-ended questions of the Questionnaire was analysed using the Statistical Package for Social Sciences 21.0 (SPSS 21.0 version), and descriptive statistics were employed to reveal mean and standard deviation scores on the Likert scale questionnaire items. Qualitative data, on the other hand, were analysed using inductive content analysis method. The findings have demonstrated that participants of the study avoid or limit the use of L1 systematically and recognize the need for giving priority to using L2 in EFL classrooms. Findings also suggest that L1 can be used as a facilitating tool in case of emergency for the sake of such functions as managing classrooms, giving instructions, checking for comprehension, establishing a friendly environment and initiating lesson using an icebreaker. The present study also identified two additional purposes of using L1; as an icebreaker and for health and safety issues. Finally, participants' perceptions of the amount of L1 use varied between 2-10% of the maximum lesson hour. Key words: The mother tongue (L1), functions of mother tongue, target language (L2), monolingualism, English teachers