In applied linguistics, being explicit about ontologies of English, and how they underpin educational ideologies and professional practices, is essential. For the first time, this volume presents a critical examination of the ways in which English is conceptualised for learning, teaching, and assessment, from both social and cognitive perspectives. Written by a team of leading scholars, it considers the language in a range of contexts and domains, including: models and targets for EFL, ESL and EAL teaching and testing, and the contested dominance of native-speaker ‘standard’ varieties; English as a school subject, using England’s educational system as an example; English as a lingua franca, where typically several languages and cultures are in contact; and English as broader social practice in a world characterised by unprecedented mobility and destabilisation. Readers are provided with a balanced set of perspectives on ontologies of English and a valuable resource for educational research and practice.