Metadiscourse – the manners in which writers and speakers interact via their language use with readers and listeners – is a broadly employed term in present discourse analysis, pragmatics and language teaching. This interest has increased over the past 40 years motivated by a dual aim. The first is a want to grasp the link between language and its contexts of use, i.e. how individuals employ language to orient to and interpret specific communicative situations, and in particular how they draw on their grasps of these to make their intended meanings clear to their interlocutors. The second is to use this knowledge in the service of language and literacy education. But this idea is not without problems of definition, categorisation and analysis. This article examines the forces and defects of the concept and maps its impact and directions via a state of the art assay of the chief online academic databases and current published research.