There are schools that require an applicant to submit a Statement of Purpose instead of a PS, the thrust of which is to present an applicant's goals in terms of what major to pursue, what research direction to take, and other specific study and career plans, if any. Therefore, in this case, you are required to submit a similar essay but with greater emphasis on your specific study and career plans. Most applicants are confused with the difference between a PS and a Statement of Purpose. This is not to say, however, that a PS cannot be a Statement of Purpose and vice versa, because as you will discover in the next section, these two can actually overlap depending on the outline you have created.
After grammar and spelling, the next problem that needs be checked is transition. Read your essay. Go through it from end to end, and check to see if your essay flows smoothly. Does each sentence flow smoothly to the next? Does each paragraph flow logically to the next? Each statement should be connected or somehow related to the one before it, not thrown randomly together. Next, limit the use of "I" in the beginning of most sentences as it is already obvious that the essay is a piece written by an individual.