Despite the fact that classroom interaction is an indispensable aspect of language learning, many EFL students do not show any willingness to participate (WTP) in classroom activities. In view of this problem, the current study aimed to describe how Iranian EFL learners’ participation in collaborative tasks can lead to WTP. Therefore, primarily discoursal features of collaborative tasks and then behavioral representations of WTP were identified. To this end, nine EFL intermediate learners (five males and four females) participated in the study and were assigned to two groups. First two collaborative tasks were designed: The first group were asked to make a digital story collaboratively and the second group were asked to make an advertisement for selling a house. The classroom interactions among students in different classrooms were video-recorded and transcribed based on conversation analysis principles. Then the frequency of the turns taken by each student was counted as indicator of WTP in the assigned task. Multimodal analysis (gaze, facial expressions, head movement, body posture and gesture) was also used to analyze behavioral representations of EFL learners’ WTP. The findings revealed that discoursal features of WTP include negotiation, elaboration, conflict, sharing expertise, humor, asking for elaboration, conflict.,and behavioral representations include eye contact, body language, and the sitting position of students which can indicate that students’ engagement in collaborative tasks can have impact on their WTP. The findings can have implications for EFL teachers, material developers, and teacher education programs.
