In this paper, an excerpt of teacher-student interaction in an EFL junior secondary science classroom in Hong Kong is analysed using the conversation analytic method of sequential analysis. The fine-grained analysis reveals that in the teacher's effort to engage her students in the co-construction of a scientific proof, the students' familiar everyday discourses (e.g. students' examples and experiences as expressed in their familiar language) need to be allowed to play a significant role. It also shows how translanguaging can be well-coordinated with multimodal practices (using blackboard drawings, gestures) to facilitate students' meaning-making in the inquiry-based teacher-student dialogue.