Effective knowledge transmission has been a key issue surrounding EMI. In EMI settings, learning a difficult subject through the medium of the students’ less proficient language may complicate the already challenging task of processing the content as listening to lengthy and information-dense lectures can be mentally challenging for listeners. In academic lectures, listeners need to understand the hierarchic and semantic relationships behind that information to create a mental representation of the spoken text. In this case, whether EMI teachers are able to make use of effective linguistic resources to facilitate teaching and learning process appears to be vitally important for the successful implementation of curriculum goals.

The present study investigates the use of interactive metadiscourse in EMI teachers’ lectures. As a rhetorical device, metadiscourse is an important means of helping audience organise, classify, interpret, and evaluate the information that speakers or writers are trying to convey. Though the function of metadiscourse in knowledge construction is acknowledged, research on metadiscourse in EMI classroom discourse is still scarce. Based on data collected from four EMI courses in two key Chinese universities, this study reveals that EMI teachers employ interactive metadiscourse in lecture organisation, science explanation, knowledge accumulation and knowledge connection. However, they tend to adopt a narrow range of expressions in achieving those purposes, which may be detrimental in terms of exposing L2 learners to target language use.