Hinderance or Assistance: A Case Study on the Application of First Language (L1) in an English as a Foreign Language (EFL) Classroom at an English Language Institution

L1 use inside EFL classrooms has been a topic of continuous discussion for a considerable period of time, with no prevailing opinion about its impact and extent within L2 (second language) learning environments, particularly within Chinese language institutions. The primary objective is to address the current gap in research and acquire a thorough comprehension of the true effects of L1 use in an EFL classroom. This was achieved through the observation of a specific teaching scenario and conducting an interview with the instructor. Data were classified using Tasçi and Aksu’s nine functions of L1 use. The results suggest that the most often observed functions of L1 in the context of education include imparting instruction, translating new terms, and attracting attention. Additionally, it was found that L1 is most frequently used during the vocabulary section and in the middle of each instructional session. Furthermore, the interviewed teacher expressed the belief that L1 usage in the classroom has positive effects, since it serves many functions and should be tailored differently depending on the students' levels of skill. This study implies that the inclusion and promotion of L2 in the EFL setting is advantageous, as learners can considerably benefit from a language immersion environment. However, L1 can still be used when deemed essential. Furthermore, during instructional sessions, educators have the opportunity to engage in reflective practices to assess the alignment between their pedagogical strategies and their intended instructional objectives.