The contributions of L1 speaking style and L2 proficiency to L2 fluency

Abstract This study examined the contributions of first language (L1) speaking style, second language (L2) proficiency, and their interaction to different dimensions of L2 fluency among adult Mandarin-speaking learners of English. Forty-one learners completed comparable speaking tasks in both Mandarin and English. Multiple regression analyses revealed that L1 speaking style significantly predicted a wide range of L2 fluency measures, including articulation rate, pausing behavior, and repetition frequency, indicating substantial cross-language association in fluency performance. L2 proficiency emerged as a significant predictor of nearly all fluency measures, suggesting that fluency is shaped not only by stable individual speaking tendencies but also by developing linguistic abilities. Interaction effects were not significant for all measures. These findings highlight the joint contribution of stable individual speaking style and proficiency-driven processing efficiency to L2 fluency and underscore the importance of accounting for L1 fluency in L2 fluency research.