What promotes success in L2 suprasegmental learning in foreign language classroom settings? The roles of perceptual, cognitive, and experiential individual differences in the acquisition of English word stress

Abstract This study investigates how individual differences in perceptual-cognitive aptitude and L2 learning experience shape the acquisition of English word stress in foreign language (FL) classroom settings, addressing gaps in prior research that has primarily focused on L2 segmental learning. A total of 119 Japanese English-as-a-foreign-language students completed a word stress identification task alongside measures of auditory processing, working memory, and L2 learning experience. Their performance was assessed in terms of both accuracy and processing fluency (reaction time and response stability). Results showed that learners with more precise auditory processing, higher working memory capacity, and more frequent L2 use outside the classroom demonstrated greater accuracy in perceiving English word stress. In contrast, classroom-based experience and the length or onset of FL learning had limited impact. Processing fluency was only weakly related to these factors, showing substantial individual variability. The findings suggest that in input-limited FL contexts, successful L2 suprasegmental learning depends heavily on perceptual-cognitive aptitude and opportunities for L2 use beyond the classroom.