The content of your essay is key, but if the delivery and execution of the storytelling is poor then you will fail to have a successful personal statement.

1. Check your spelling.  There is no reason to have spelling errors.  If you have spelling errors then that means you are not careful and/or lazy, which are two characteristics not desired in a potential medical student.

2. Check your grammar.  Your grammar checker can probably help you with identifying sentences in the passive tense or incomplete sentences, but sentence structure is best left for human readers.  Check for punctuation errors.

3. Check for homonyms.  Here is a list of homonyms (http://www.cooper.com/alan/homonym_list.html).  They are words that sound alike but have different spelling and meanings.