Effects of translanguaging and task rehearsal on L2 speaking performance

Abstract This study investigates the effects of task rehearsal and translanguaging during strategic pre-task planning on English-as-a-foreign-language (EFL) learners’ L2 speaking performance, drawing on the complexity, accuracy, lexis, and fluency (CALF) framework. A total of 128 Chinese university EFL learners completed two parallel problem-solving monologic tasks under different planning conditions (translanguaging vs. L2-only planning) and task implementation conditions (with vs. without rehearsal). Linear mixed-effects modeling revealed that while task rehearsal improved breakdown fluency, as evidenced by reduced mid-clause pause duration, it impaired repaired fluency, leading to more frequent self-repair and repetition. However, task rehearsal had no significant effects on complexity or accuracy. Learners in the L2-only planning condition outperformed the translanguaging group in (reduced) mid-clause pausing and (faster) speech rate, suggesting greater formulation efficiency under L2-only planning. Importantly, a significant interaction effect of rehearsal and language planning on L2 speech performance was observed, showing that while rehearsal reduced pausing and increased speech rate under L2-only planning, it increased speech rate without alleviating pausing under translanguaging planning. Interpreted through Levelt’s speech production model and Skehan’s limited attentional capacity framework, the interaction effect indicates that task rehearsal may support conceptualization while imposing additional processing demands at the formulation stage in the translanguaging condition. The study concludes with implications for task design and the strategic integration of translanguaging in L2 speaking instruction.