The expansion of English teaching in state education systems places increasing demands on English language teachers and how they are trained. A major thrust of these efforts has focused on improving teachers' English language proficiency. This expectation is manifested in policy and pedagogical directives that teachers 'teach English in English'. We argue for a reconceptualization of teacher language proficiency, not as general English proficiency but as a specialized subset of language skills required to prepare and teach lessons. This concept of English-for-Teaching as a bounded form of English for Specific Purposes (ESP) for the classroom builds on what teachers know about teaching, while introducing and confirming specific classroom language. This article describes how the construct was developed and then describes sample classroom tasks and the language needed to enact them in three major areas: managing the classroom, understanding and communicating lesson content, and assessing students and giving feedback.