Quote Originally Posted by Xander416 View Post
Depends on where and by what kind of character it's being used. My rule is that if it's narrative or spoken dialogue by a character that's supposed to be abnormally intelligent (i.e., Stephen Hawking or Sheldon Cooper), don't do it. If it's spoken by an average person, it's fine because average people talk like that. Same rule I apply to words like "ain't" and "irregardless", actually.
I think Stephen Hawking would be intelligent enough to recognise how stupid the "rule" is and would end his retort with the preposition, off.