This book provides a re-conceptualization of grammar in a period of change in the communication landscape and widening disciplinary knowledge. Drawing on resources in systemic functional linguistics, the book envisions a 'functional grammatics' relevant to disciplinary domains such as literary study, rhetoric and multimodality. It re-imagines the possibilities of grammar for school English through Halliday's notion of grammatics. Functional Grammatics is founded on decades of research inspired by systemic functional linguistics, and includes studies of grammatical tools useful to teachers of English, research into visual and multimodal literacies and studies of the genre-grammar connection. It aims to be useful to the interpretation and composition of texts in school English, portable in design across texts and contexts and beneficial for language development. The book will be of interest to researchers and teacher educators, as well as undergraduate and postgraduate students and practicing teachers committed to evidence-based professional development.