Using Conversation Analysis, this paper explores EFL trainee teachers’ orientations to students’ displays of non-understanding in instruction giving sequences. The analyses draw on sequential organisation of talk as well as on various multi-semiotic resources the participants deploy including orientations to classroom artefacts (e.g. interactive whiteboards). The research utilises transcriptions of 13 (classroom) hours of video recordings of 13 different EFL teachers’ classes. The data were collected over a semester in 2013 in a public secondary school in Turkey. The findings show that students’ displays of non-understanding (e.g. through statements like “we did not understand” or by initiating requests for clarification) in instruction giving sequences are important sites for teachers to ensure clarity, as understanding of these instructions by the students are crucial for task accomplishment. Based on a collection of cases, we demonstrate that teachers may turn displays of non-understanding to understanding by using resources like multimodal explanations and modelling. However, the majority of cases in instruction giving sequences include teachers’ lack of or limited orientations to students’ non-understanding. We argue that management of non-understanding in such sequences should be integrated into teacher education curricula in both content and language classrooms, as they play an important role in ensuring task accomplishment.