I was raised to be a grammar Nazi, so I thought I had it all sewn up when I started into a Master's in Linguistics. Hmmph!!! The first lesson was on the difference between Prescriptivism and Descriptivism. The instructor explained that Prescriptivists tell people how to speak their own language while Descriptivists accept language the way it is spoken by a group of individuals. What??? No more standards? Nope, none. Whatever you write or say is OK.