Commonly, English language teachers determine language appropriateness within the parameters of the ‘fixed entity’ of English as a native language. Much less commonly, they exchange information specific to ELF-aware classroom practice. Such exchanges, taking into account learners’ current and potential communication contexts, can address issues such as the concern that teachers’ unselective targeting of native competence may inhibit learning processes. They can shed light on some assumptions in English language teaching, for example that intelligibility is norm-driven. ELF-awareness can enable a shift in attention from linguistic competence to communicative capability, and a focus on the ability of a speaker to use the underlying resources of the language rather than just the conventional encodings. Teacher decision making about ELF is ultimately a local matter; teachers need extensive information in order to reorient their convictions meaningfully and critically.