The Impact of Content and Language Integrated Learning on English Speaking Proficiency: A Mixed-Methods Study in Chinese Tertiary Education

Content and Language Integrated Learning is recognized for its potential to enhance language proficiency while fostering content mastery, particularly in multilingual and globalized education systems. However, its impact on English-speaking proficiency, particularly in the Chinese tertiary education context, remains underexplored. This study addresses this gap by examining the effects of a 12-week Content and Language Integrated Learning intervention on the speaking complexity, accuracy, fluency, and pronunciation of Chinese university students. The study is significant because it extends current understanding of how CLIL influences different dimensions of speaking proficiency in higher education and provides evidence-based insights for improving English language pedagogy in the Chinese tertiary context. Employing a mixed-methods approach, quantitative data were gathered through pre- and post-tests, complemented by qualitative insights from classroom observations and student interviews. The findings revealed that the intervention significantly improved fluency and pronunciation, yet had limited effects on speaking complexity and accuracy compared to traditional instruction. Qualitative data highlighted that meaningful communication tasks fostered confidence and spontaneity in speaking but lacked a focus on explicit grammar and vocabulary instruction, leading to cognitive overload in balancing content comprehension with linguistic refinement. The study underscores the need for integrating form-focused instruction into Content and Language Integrated Learning frameworks to achieve balanced language development. These findings provide valuable implications for teachers and curriculum planners, emphasizing the importance of harmonizing content and linguistic objectives to optimize the dual focus of Content and Language Integrated Learning in English language education.