A lot of people say that the GMAT essays are meaningless, but don’t forget that they can be a determining factor in the increasingly competitive admissions process. An extremely low score could set off flags and trigger concerns about your ability to complete graduate-level work. Also don’t forget: Admissions officers will use your GMAT essay as a check on your personal statements, to make sure they were authored by the same person (you).
For those of you who read a lot and have a good grasp of grammar, relying on your intuition will get you through most questions. Learning the concrete, “math-like” way that a seemingly alright sentence violates GMAT a grammar guideline will get you through those tougher questions. Famous authors often violate GMAT grammar guidelines, and it’s important to learn what the GMAT specifically deems wrong.
As of June 5, 2012, there is only one essay on the GMAT: Analysis of an Argument. This essay requires you to analyze the reasoning behind a given argument, and assess that argument. You do not need to present your own point of view in the Analysis of an Argument essay. The AWA is scored on a scale from 0-6, and is an average of scores from the two graders who will read your essay.