اشرف بیضایی

Second language (L2) theories have for long acknowledged the importance of focus on formulaicity or conventionalized lexical chunks. Yet, there has been little attempt to examine the impact of this on foreign language learners’ development of complexity, accuracy, and fluency (CAF) measures. The purpose of this study was twofold: First, to see whether lexis-based instruction had any significant effects on EFL learners' oral CAF, and, second, whether different types of lexis-based instructions (e.g., using corpus-based concordances, textual lexis enhancement, and audio-visual captioned lexis) had differential effects. Participants were 54 EFL undergraduates at an Iranian university. After checking the initial homogeneity, <em>2</em> groups of participants were randomly assigned to experimental (lexis) and control (non-lexis) groups. After pretesting on CAF, the lexis sub-groups received the <em>3</em> types of lexis-based instructions in a counterbalanced manner. After each lexis instruction, students’ oral data were also obtained. The control group received mainstream non-lexis instruction. One-way MANCOVA results pointed to the significant effects of lexis instruction on oral CAF measures. Specifically, repeated-measures MANOVA results revealed that audio-visual captioned lexis was the most effective modality in heightening formulaicity. The findings suggest that focus on lexis is beneficial to L2 learners’ oral skills. Further theoretical and pedagogical implications are discussed.