Here's a little tool I found earlier today - spelling & grammar checker! >> http://spellcheckplus.com/ Since grammar is not the most popular thing around , and also for many users here English is a foreign language, I think this tool could be pretty useful. It's not perfect though, but performs well in most cases. Enjoy!
It doesn't really work for me. I don't think any of them do. You can still write sentences that make no grammatical sense and it clears them, this is the sentence I wrote and it said it was okay. lol . Nothing beats manual proofreading!
But what it won't find are words that aren't spelled wrong but are used incorrectly: I like there house. The monster loves it's cave Your coming over, right?