2018 Elsevier Inc. This article combines a sociocultural model of classroom talk with a linguistically-oriented model (systemic functional linguistics) to explore what characterizes effective asynchronous online discussion in higher education (HE). While the benefits of discussion are commonly accepted in face-to-face learning, engaging students in effective asynchronous discussion can often be 'hit or miss' due in part to the shift to interacting asynchronously. This hybrid mode of spoken-like/written-like communication demands skills which are rarely made explicit, often with the assumption that students (and lecturers) are proficient. The combined framework presented here enabled macro- and micro-understandings of discussion forums through an array of resources in the SFL model and the talk type descriptors to map linguistic features of knowledge constructing talk in an Australian postgraduate HE context. The notion of 'listening' (or attending to others) is proposed as a crucial condition for whether discussion progresses beyond simply 'posting'. Consequently, this article provides much needed insight into the murky space of asynchronous discussion forums.