If you don't understand the material being presented, ask for clarification. If the instructor's answers do not resolve your confusion, don't give up. Show with body language that you are actively participating. For example, by nodding when you understand and frowning when you don't, you can let the instructor know how much you understand. Talk with your instructor early in the semester.
Communication is essential to learning.
To enhance communication with your instructor talk informally with him or her after class or during office hours. Share your background experience in the subject and let your instructor know if you are experiencing any difficulties. If your instructors accent is different from your accent or if she or he uses unfamiliar vocabulary, talking informally during office hours will help strengthen your comprehension skills. Informal conversation is an easy place to strengthen the communication with your instructor because you can ask for clarification as you go along. The skills you learn in communicating informally in the office hour will also transfer to the class or lab setting.