Many people are afraid to discuss in class, but open dialog provides an excellent learning situation. If you have a different opinion from your teacher, go ahead and say it. Make certain that your opinion is based on facts and evidence, not just something you made up.
To take part in a discussion, follow what everyone is saying. When something is said that you feel should be noted or discussed more, write it down. Don't be afraid to ask a question if you do not understand something or follow the thread of the discussion. Answering questions can be quite beneficial in a classroom situation.

It is a good idea to briefly summarize your point when you enter the discussion. Sometimes restating the idea is a way to start talking. By restating the idea, you have reinforced the statement and possibly provided some clarification.

Refer to your notes if necessary, and don't be afraid to state your position. Just don't ramble and keep talking. Make your point then let somebody else answer you or give another idea.

People may or may not agree with you. Don't get upset. Keep an open mind. Open dialog is important in the classroom, and academic freedom is highly regarded. Remember to respect others opinions and reactions.

If you are aware of class discussion, look over your textbook and notes before coming to class. Think about your opinion and ideas before coming into the classroom. Have an idea of your opinion.