Abstract: The purpose of this paper is to explore the main body of literature on motivation in second language learning. It aims to discuss the major theories of motivation on the influence of teachers on learners’ motivation and to explain how teachers can generate and maintain motivation in their teaching practices. Based on the vast body of research on motivation, this paper suggests that teachers have a huge responsibility to initiate learners’ motivation and keep it alive throughout the learning process. Moreover, it synthesizes the conclusions drawn from the literature on motivation conducted to identify strategies and principles appropriate to be used by teachers in their classrooms.