Metadiscourse – the ways in which writers and speakers interact through their use of language with readers and listeners – is a widely used term in current discourse analysis, pragmatics and language teaching. This interest has grown up over the past 40 years driven by a dual purpose. The first is a desire to understand the relationship between language and its contexts of use. That is, how individuals use language to orient to and interpret particular communicative situations, and especially how they draw on their understandings of these to make their intended meanings clear to their interlocutors. The second is to employ this knowledge in the service of language and literacy education. But while many researchers and teachers find it to be a conceptually rich and analytically powerful idea, it is not without difficulties of definition, categorisation and analysis. In this paper I explore the strengths and shortcomings of the concept and map its influence and directions through a state of the art analysis of the main online academic databases and current published research.