- Not, nor, and no are English words by themselves - Not: Not is a negative qualifier for an object otherwise assumed to be affirmative. (source: http://www.sciforums.com/threads/what-is-the-opposite-word-of-not.64611/) Example: He is tall. He is not tall. (Cant use "nor", "non", or "no" here) - Nor: Nor is another way of saying "or" in sentences where the verb is in the negative. "Nor" isn't used as often, and it sounds a bit formal or stuffy. Just like "or", something has to come before "nor"; you can't start a sentence with it. The format is: [first part of sentence], nor [verb][subject][rest of sentence] Examples: He didn't call or visit / He didn't call, nor did he visit. // I won't take out the trash or do the dishes / I won't take out the trash, nor will I do the dishes. - Non is a suffix; something that is attached to words to negate their meaning Example: nonbeliever, nonstop, etc. - No: no is the opposite of "yes". It can be used as a response all by itself.