<![CDATA[While prior research establishes that participation is affected by proficiency, instruction, motivation, and anxiety, few studies investigate participation by integrating obesrvable classroom behaviour with teachers' interpretations, particularly within Indonesian university EFL context. To bridge this disparity, this study aims to describe how university students with varying English proficiency levels participate in EFL classroom and to explore how teachers interpret university students' participation in light of those prificiency levels. This research applied a case study design and was cinducted in an English Intensive program at an Islamic university in Surabaya, Indonesia. Ten students from two classes and five teachers were involved. Data were collected throuh non- participant classroom observation and in-depth interview with university students and teachers, and were analyzed using thematic analysis to identify patterns of participation and teachers' interpretations. The study found that students' participation appeared in many forms and was not limited to speaking. Higher and immediate prficiency students tended to participate verbally, mostly when prompted by the teacher. Meanwhile, lower proficiency students participated by listening, taking notes, following instructions, and completing tasks. Teachers interpreted participation by considering students' participation level, confodence, task difficulty, and classroom situation. Silence was often viewed as limited language ability or low confidence rather than a lack of interest. The study contributes to a deeper understanding of classroom involvement in EFL classroom environments. The study supports the notions that participation is dependent upon context and socially created, rather than just verbal. It also shows that observed stillness, can indicate cognitive engagement rather than disegagement. By combining teachers' perspectives with students' behaviors, this study implies that participation should be investigated through both behaviour and interpretive lenses. Future reserach should explore classroom participation and consider linguistic, non verbal affective, and contextual elements. ]]>
