Participation in the ESL classroom is indispensable for students to improve their English skills. By increasing student interaction during class you will encourage participation, and students will have a better chance to develop their language skills more successfully.
For most students, their English class is one of the few moments in the day, or the only time, when they have a chance to use their spoken English. If they do not participate, their oral skills fall behind and they lose confidence as time goes by instead of gaining it. Telling students that participation is beneficial for their language development and improvement is often not enough to motivate them to participate.