Factors Influencing the Use of L1 in Teaching Grammar Class of Prospective ESL Teachers in a Philippine Higher Education Institution

This study aimed to explore the use of Language 1 (L1) in the Teaching Grammar class of 24 prospective English as a Second Language (ESL)/(L2) teachers in a Philippine Higher Education Institution. The majority of the research that has been done on L1 usage in language classes is oriented on teachers' opinions, with little attention paid to students' viewpoints directly or in-depth. This study aimed to highlight this disparity and stimulate more investigation into students' views on L1 usage in an English course. This study used a sequential explanatory mixed-method research design, utilizing observation and semi-structured interviews to gather necessary data during the second semester of school year 2023-2024. The study revealed that most participants used their L1 during their Teaching Grammar class. Using their L1 to communicate complex data helps them engage more deeply with the topic. However, it hinders the growth of English as the academic language. Anxiety and limited vocabulary were the factors unveiled. Anxiety may have been induced by past experiences, societal expectations, or academic constraints. Moreover, the participants frequently code-switch since they lack vocabulary. This suggests the need for vocabulary-building strategies. Hence, the findings highlight the need for targeted strategies to support students in their language learning journey. School administrators may provide facilities or learning resources for curriculum implementers to include in language-acquisition activities. Future researchers may delve into action research by using strategy and intervention materials.