Thirty-Five Years of Research on Idioms in Second Language Acquisition: A Methodological Review

Researchers in the field of second-language acquisition have long been interested in studying idioms. However, one important issue that has been overlooked is the lack of a comprehensive review addressing the methodological approaches used in idiom studies. This methodological review aims to fill this gap by providing a systematic overview of the main methodological characteristics of research conducted on the learning and teaching of idioms over the past 35 years (1990–2024). To accomplish this, the review first highlights the need for conducting a review study on idioms followed by a theoretical framework to discuss the concept of idioms from different perspectives. It then outlines the procedures and steps taken to identify and select relevant studies based on PRISMA. The alignment with the SMART guideline is then illuminated. Finally, the findings of the review of the selected articles are presented, discussing the range of methodological features employed in idiom research. This review serves as a foundational resource for advancing methodological rigor in idiom studies and guiding future research.