Everyone, even the editor pros, need hep form time to time with grammar. Grammarly is an automated proofreader that, like your 5th grade English teacher, will check for grammatical mistakes. (But without the red pencil marking up your paper and the embarrassing grade.) The site will not only check for over 250 types of grammatical errors, it will also offer suggestions, enhance writing, and check against plagiarism. You can try it for free and see if it fits your needs. Pretty darn cool.