This study reveals that debating experiences can play an important role in facilitating student expression of opinions on controversial issues, nurturing critical thinking ability. In order to express opinions clearly and persuasively, critical thinking is necessary to generate effective argument and analysis. The students learned how to be persuasive and appreciated the opportunity to gain multiple perspectives by listening to others’ opinions. However, the extent of persuasiveness differed depending on level and degree of cognitive awareness concerning persuasiveness, basic English skills, and the level of the ZPDs. This study also demonstrates that the debating activity contributed to creating a learning environment in the EFL classroom where learners share interests and learn from each other. As the Community of Practice (CoP) model suggests, the students are practitioners who developed a shared repertoire and resources through the activity, which in turn helped them write more persuasively.
