Analyze: This is the killer, but unfortunately they seem to like this more and more. Just remember: they're not looking for an opinion, they're looking for an analysis. That is to say, they want to see you explain more than opinionate.
Compare: This just means to look at it and see the similarities. Again, try to impart understanding, but this time they are looking for opinions.
Contrast: Same, just look at the differences instead of the similarities.
Describe: This means to narrate, to tell a story, and to give an account of something.
Discuss: When this is used, you want to give arguments, pro and con, for what they are saying.
Evaluate: Which factor was most important. You usually need to rank several events or factors and specify which is most and which is least significant.
Explain: Give an explanation; make things clear. Remember, the reader assumes NOTHING!
To what extent...?: This is also an opinion question. It asks you to look at the statement, and tell to what degree it is true. There is no one right answer, and two conflicting answers may both get tens. However, you must back up your statements!!! This goes for all essays, too.