Monolingualist claims for the importance of 'speaking English' continue louder than ever - even as language diversity is increasingly part of contemporary British life - causing literature to consider the terms of linguistic belonging. Bad English examines writers including Tom Leonard, James Kelman, Suhayl Saadi, Raman Mundair, Daljit Nagra, Xiaolu Guo, Leila Aboulela, Brian Chikwava, and Caroline Bergvall, who engage multilingually, experimentally, playfully and ambivalently with the power of English. Considering their invented vernaculars and mixed idioms, their dramatised scenes of languaging - languages learned or lost, acts of translation, scenes of speaking, the exposure and racialized visibility of accent - it argues for a growing field of contemporary literature in Britain pre-eminently concerned with power dynamics, language's aesthetic potentialities and its prosthetic strangeness. Drawing on insights from applied linguistics and translation studies, as well as literary scholarship, Bad English examines contemporary arguments about language in Britain, through debates about citizenship or education, in the media or on Twitter, in Home Office policy and asylum legislation and how this is taken up in literature. It uncovers an antagonistic and a productive interplay between language politics and literary form, tracing writers' articulation of linguistic alienation and ambivalence and the productivity and making-new of radical language practices. Doing so, it refutes the view that language difference and language politics are somehow irrelevant to contemporary Britain and argues for their constitutive centrality to the work of novelists and poets whose inside/outside relationship to English in its institutionalised forms is the generative force of their writing.