Multi-word expressions and communicative engagement: A longitudinal study of L2 learners’ willingness to communicate

Abstract Despite growing interest in willingness to communicate (WTC) in second language (L2) research, the role of multi-word expressions (MWEs) in fostering communicative engagement remains underexplored. This longitudinal mixed-methods study examines the impact of MWEs on WTC development among L2 learners. Over twelve months, seventy-seven intermediate-level learners participated in an experimental design where MWE knowledge and WTC were assessed at five time points. The experimental group (n = 58) received explicit MWE instruction, while the control group (n = 19) followed the standard curriculum. Data collection included WTC scales, MWE recall tests, structured classroom observations, and learner interviews. For the MWEs and WTC data, mixed ANOVA and hierarchical regression modeling were used to test whether MWE gains predict WTC increases; and for the observation data, descriptive statistics were utilized. Qualitative data were also analyzed through thematic coding. Quantitative analyses revealed that MWE gains significantly predicted increases in WTC over time. Qualitative findings corroborated these results, showing that MWEs enhanced communicative confidence and encouraged risk-taking. The study underscored the need for integrating MWEs into L2 instruction to foster greater communicative engagement.