Teacher questions are claimed to be constitutive of classroom interaction because of their crucial role both in the construction of knowledge and the organization of classroom proceedings (Dalton Puffer, 2007). Most of previous research on teachers’ questions mainly focused on identifying and discovering different question types believed to be helpful in creating the opportunities for learners’ interactions. Drawing on conversation analysis through adopting socio-cultural perspective, this study, however, aims to examine how EFL teachers manage understanding-check questions in their talk-in-interaction. For this purpose, six EFL teachers’ discursive classroom practices were observed, video-recorded, and transcribed line-by-line in its entirety. Through the microanalysis of the transcribed data, our findings suggest that EFL teachers vary in their management of understanding-check questions and the teachers’ understanding-check questions tend to serve different functions in the different micro-contexts identified. Three major sequential environments emerged to feature understanding-check questions in this study: Activity-boundary environment, post-instruction environment and within-activity environment. The findings of the study indicate that understanding-check questions at activity boundary environment are designed to accomplish dual functions, however those launched in post-instruction and within-activity environments maintain a singular focus on ensuring absolute understanding of the just-given explanation or instruction.