LAUSR

Abstract Many researchers with English as an additional language (EAL), as well as EAL teachers and students, believe that idioms are not used in English academic speech or writing. By 'idiom', they usually mean an expression that is figurative, opaque, multiword, largely fixed, and institutionalised, in keeping with traditional EAL textbook definitions. By contrast, researchers addressing multiword expressions in academic corpora have frequently used the term 'idiom' very broadly, resulting in lists that include lexical bundles and other types of collocation, rather than more traditional idioms. This study identifies all the traditional, textbook-type idioms in the British Academic Spoken English (BASE) corpus, examines the range of texts in which they appear, then compares their frequency to the same idioms used in the Oxford Corpus of Academic English (OCAE). The resulting list of 545 idioms, 56 of which appear in four or more BASE texts and 43 of which appear at least 100 times in OCAE, can be used confidently by EAL writers and teachers to enrich their own and their students’ English academic speech and writing.