Flipped Learning of English Idioms by Low and Upper Intermediate L2 Learners: Does Proficiency Make an Impact?

The acquisition of multiword expressions (MWEs), particularly idioms, plays a crucial role in achieving native-like fluency and communicative competence in English. However, effective pedagogical approaches for teaching idioms remain insufficiently supported by empirical evidence, particularly technology-enhanced methods such as flipped learning in second language (L2) contexts. This quasi-experimental study investigates the impact of flipped learning compared with traditional non-flipped instruction on the idiom acquisition of low and upper intermediate L2 learners. A total of 195 Iranian English as a Foreign Language (EFL) learners were selected and assigned to experimental and control groups within each proficiency level. The experimental groups received flipped instruction over five sessions involving pre-class exposure to instructional materials via the Skyroom platform, while the control groups received traditional teacher-centered instruction during class time. Analysis of data collected from form-recall and meaning-recall tests revealed statistically significant differences between the flipped and non-flipped groups at both proficiency levels, with the experimental groups outperforming the control groups. The findings suggest that flipped learning enhances idiom retention and comprehension, regardless of learners’ proficiency level.