The analytical writing section is divided up into 2 essays: a critique and an opinion piece. Part of the score is determined by how well you separate your personal opinions from analytical arguments, and how well you stay on topic.
The Opinion Essay: "Present Your Perspective"
The opinion essay provides you with two statements, one of which you much choose to answer. You are to give your personal opinion concerning the statement, agreeing with, disagreeing with, or qualifying the statement. You must not analyze the given statement, and you must not talk about other subjects. This is an important point, because this essay will be graded according to how well you stay on topic. If you don't stay on topic, you will lose points. The skill with which you write is not nearly as important as your ability to focus on the topic.
The Critique Essay: "Analyze an Argument"
The critique essay provides you with an argument, often of dubious quality. Your task is to read the given passage, and analyze the logic of the assertion within the essay. You may accept or deny that the position presented is well-reasoned, but you must support this. (It is usually easier to find and discuss any logical flaws than to demonstrate that the brief argument is sound.) You must not use your personal opinions when writing this essay, and you must not speculate. You may only discuss the information that is provided, and you can comment on additional information that should be included. Again, your ability to follow the rules is much more important to the judges than your ability to write beautiful sentences. The opinion essay asks you to express your opinions and not critique the argument, while this essay asks you to do exactly the opposite. Check your emotions and opinions at the door, because if you start to express your opinions, you will lose points. The most difficult aspect of this essay is to separate the logical facts of the argument from your personal feelings on the issue. If you can separate these well, you will get a good score.
Sample Essay Questions
The GRE website contains a large listing of sample essay questions. It is a good idea to read through this list, and get a good idea of what kinds of things the GRE is going to ask. Do not bother trying to memorize this list of questions, or to prepare essays ahead of time, unless you are just practicing. The phrasing of the questions may vary enough from the list to affect any prepared answers.