Abstract
<jats:p>This study explored how pre-service mathematics teachers navigated linguistically diverse classrooms, focusing on how they employed code-switching and multiple languages in teaching, how they perceived its pedagogical role, and what challenges and strategies emerged from these practices. Drawing from classroom observations and interviews, findings revealed that teachers strategically used Tagalog and English, with minimal use of Sinug—the students' mother tongue. Code-switching served as a bridge for comprehension, an entry point for engagement, and a tool for participation and confidence-building. However, teachers faced challenges such as difficulty translating mathematical terms, uneven language proficiency, and pacing strain. In response, they developed adaptive strategies like visual scaffolding, iterative explanation, and peer translanguaging. Overall, the study underscores that language in mathematics is not neutral but deeply pedagogical, shaping access, equity, and belonging in multilingual classrooms.</jats:p>