Rocky Elsom (76)
This is a good topic, one where we can vent our frustrations. Mine is "should of, could of, would of, must of". Nothing demonstrates the failure of modern education to teach basic English grammar more than those examples. They're supposed to be "should have, could have, etc" or the contraction "should've, could've, etc".
Concur. Reading "should of", "could of", "would of" is an equivalent to hearing fingernails screeching down the blackboard.