Abstract
Strategic code-mixing has become a common instructional practice in multilingual classrooms; however, existing studies have largely focused on students’ language use, attitudes toward bilingual communication, and general sociolinguistic patterns, with limited attention given to intervention-based investigations of teachers’ strategic use of code-mixing and its effects on student learning. This action research examined the impact of strategic code-mixing on instructional delivery and student learning in Junior High School classrooms at Mindanao State University–Integrated Laboratory School (MSU-ILS). Guided by Kemmis and McTaggart’s Plan–Act–Observe–Reflect framework, the study employed a mixed-methods design involving six teachers from English, Science, and Mathematics and 90 Grade 7 students. Data were collected through pre- and post-intervention Likert-scale questionnaires, classroom observations, and open-ended student reflections. Findings revealed substantial improvements in teachers’ awareness of instructional language use, increasing from a moderate level (M = 3.41) to a high level (M = 4.49) following the intervention. Teachers also demonstrated stronger agreement regarding the pedagogical value of code-mixing (M = 3.54 to M = 4.56), particularly in clarifying complex concepts, reinforcing instructions, and sustaining learner engagement. Post-intervention results further indicated positive perceptions of code-mixing’s influence on student comprehension and participation (M = 4.54). Qualitative findings supported these results, with students reporting greater confidence, improved understanding, and increased classroom participation when Filipino was strategically integrated into instruction. The study concludes that strategic code-mixing serves as an effective language-responsive instructional approach that bridges linguistic gaps, reduces affective barriers, and promotes inclusive learning environments in multilingual educational contexts.
Keywords: Action Research, Instructional Delivery, Multilingual Education, Strategic Code-mixing, Student Engagement.