Hello,
Yes, seminars! When I was an undergraduate I sometimes used to feel afraid to speak in seminars. I sometimes found it difficult to follow the arguments that were being made in the seminar (especially when I studied Philosophy!!). And, of course, when you believe everyone else understands the discussions, you begin to think you're the only one who doesn't understand, and so you sit there quietly feeling stupid

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But you can also be quite wise in seminars. You can sit and listen carefully to what everyone else is saying. Try observing the others who speak - how many of the group speak the most? You may find that just one or two dominant or confident individuals do most of the talking. So just listen and think about what they say. Then, when you get an opportunity, you can say something like, "I thought Gina's point about inflation was very interesting." or "I agree with Peter's point about global warming."
Remember that in seminar discussions there's really no right or wrong answer - discussion is a way of arriving at new understandings and ideas. Nobody is judging what you say - all opinions are valid.
But, as eaptutor1 says, it's absolutely essential that you do the relevant reading before you go to the seminar. But don't just read the articles: make notes of the key ideas and any interesting facts or opinions you find in the articles. Write these ideas down on note-paper, make a note of your own opinion on the ideas, and then take your notes with you to the seminar. Then you can refer to them during the discussion. And, if the tutor asks you a question, you can at least quote from a text and say something like, "I thought this idea, by Philips et al, was very interesting."
So, don't panic! Just prepare your knowledge of the topic and enjoy the discussions!
Good luck!!
