Spellchecker

Before a couple of days, I submitted proposal of my masters project to my professor. He replied saying "English is not good". I have always suffered using the right tense or verb in the sentence. So I looked online for a tool which can point out my grammar mistakes. I found http://www.spellchecker.net/spellcheck/ which checks spellings and grammar. I also found another http://community.languagetool.org/.I will have to use it untill I become Mark Twain. :)