In honor of National Grammar Day, John McIntyre has a nice post explaining why much of what we have been taught regarding grammar and usage rules ultimately amounts to a “proliferation of bogus advice on language.” It’s an interesting historical overview that explains how
without an Academy to determine an authoritative English, and without the ability of dictionary makers to “fix” the language, the task of establishing principles of grammar and usage has fallen to a mixed group authorities of varying reliability.
So all those ironclad rules about split infinitives and sentence-ending prepositions that teachers harped on, and much of the stuff in the AP stylebook, is basically derived from little more than self-reinforcing cycles of personal preference. Good times.
McIntyre also links to a fun anti-Grammar Day post at Language Log. Both well worth checking out.