Teachers always give them at some point or another. But some are awful and stupid. For example, my social studies teacher told us that we would have a test on everything we learned this year with 1 week to prepare and no study guide. This doesn’t seem fair, she usually gives the class a study guide 2 weeks before a test. But since it is only like 1/2 our grade we obviously don’t need a study guide. Teacher logic makes absolutely no sense.