Idiomatic expressions, commonly considered as a figure of informal and spoken language, have been so far neglected in English for Academic Purposes (EAP) studies which have investigated different aspects of research articles, as a specific academic genre. However, idioms have been recently found to be employed in academic discourses (Simpson & Mendis, 2003). This study, as one of the first attempts, aims to investigate idioms in a corpus Applied Linguistics research articles written by native English-speaking writers to fill the void in the literature and to examine the idea of compiling a list of written academic and genre-specific idioms in further studies. More importantly, the study aims to analyze different aspects of idiom usage along with the pragmatic functions they perform in the articles. To these aims, NVIVO software was used to analyze 300 randomly selected articles collected from five well-established journals of Applied Linguistics. Results indicated that idioms perform six pragmatic functions in different sections of research articles and that idioms are most commonly used to perform an emphatic function in research articles. It was also found that idioms can perform functions uniquely related to research articles and different from other genres. A list of the most frequently used academic idioms (e.g. shed light on, call into question, pave the way) along with their functions in research articles was compiled which can be applicable to EAP contexts and EFL writing courses.
