In-service teachers’ perceptions, experiences, and strategies in CLIL: a study of in-service school teachers in Thailand

This study explores Thai in-service teachers’ perceptions, experiences, and strategies related to implementing Content and Language Integrated Learning (CLIL) in primary and secondary schools. The research aimed to (1) examine teachers’ perceptions of CLIL, (2) investigate their instructional readiness and professional development, and (3) identify classroom language strategies used to integrate content and language effectively. An explanatory sequential mixed-methods design was employed, beginning with a questionnaire completed by 42 teachers, followed by in-depth interviews with 8 participants. Quantitative results showed that most teachers viewed CLIL positively, especially in enhancing student engagement, English communication, and subject comprehension. However, challenges such as limited training and balancing content with language instruction were common. Thematic analysis of the interviews revealed three key themes: (1) CLIL Perceptions and Student Engagement, (2) Classroom Language Strategies for CLIL Teaching, and (3) Teacher Development and Readiness for CLIL. Teachers highlighted the use of scaffolding techniques such as visuals, simplified language, and peer support and stressed the need for more structured training and institutional support. The findings underscore the importance of targeted professional development to build teacher confidence and ensure the sustainable implementation of CLIL in Thai EMI classrooms.