Often inaccurately defined as a
Grammar Nazi (even here on the
Urban Dictionary, see tags), a Grammar Troll is, most simply, someone who corrects the grammar of other people. Grammar Nazis may also correct grammar, but there are differences to be noted.
1) Grammar Trolls have no inhibition. They will correct all
grammatical mistakes they see. Unlike a
Grammar Nazi, they will correct trivial spelling a punctuation errors and nitpick word choice, especially when those minor errors or diction do not affect the meaning of the statement.
2) Grammar Trolls will do nothing but correct grammar. Most Grammar Trolls are aroused when finding themselves in arguments they realize they cannot win. That is when they resort to pettily correcting the most trivial mistakes, especially the misuse of homophones, in an attempt to undermine their opponents' credibility while not actually attempting to refute their opponents' points nor defend their own.
3) A Grammar Troll may use improper grammar while making these corrections and attacks. It is important to note that even true Grammar Nazis make mistakes. However, if while correcting someone a person makes a painful grammatical blunder that should not have been made, especially if multiple are made in succession, that person is a Grammar Troll.
4) Grammar Trolls are generally assholes. Generally, a
Grammar Nazi will be respectful in correcting grammar. But a Grammar Troll is in almost all cases condescending, smug, and spiteful.
