Navigating Affective Cues in Video-Based Instruction: The Role of Instructor Emotions and Idiom Valence in English Idiom Acquisition

EFL vocabulary learning is an emotionally rich process, particularly in video-based instruction where learners encounter multiple affective cues. This mixed-methods study examined whether instructors’ emotional expressions and idiom valence influence EFL learners’ idiom acquisition and learning experience. A 3 × 3 within-subjects experimental design was adopted, manipulating instructor emotion (positive, neutral, and negative) and idiom valence (positive, neutral, and negative). Forty-five undergraduate EFL learners from a university in China participated in the study. After viewing each video, participants completed an immediate idiom recall test, a perceived learning experience scale, the self-assessment Manikin scale, a cognitive load scale and an open-ended questionnaire. The results showed that neither instructor emotion nor idiom valence had a significant main effect on immediate idiom recall. However, a significant interaction effect was observed, although follow-up comparisons did not identify a robust advantage for any specific congruent or incongruent condition. These findings provide implications for the emotional design of instructional videos in EFL vocabulary learning.