You know what bugs me? The "could of" phrase.
Now, I understand that language shifts. I also understand that some people have difficult with the English language.
But the people I see using "could of" are native English speakers. And no matter how much language shifts, it usually makes SOME linguistic, grammatical, or etymological sense. "could of" does not.
"could of" sounds right out loud. IF YOU WERE TRANSLITERATING APPROXIMATE SOUNDS. If the context of the phrase is "could've" then that's exactly what the fucking phrase should be, NOT "could of".
Now, "could've" does not register as a proper contraction in general ("would've", however, does, and yes, I've also seen the "would of" structure; it is just as aggravating) but it makes a hella lot more sense than "could of". I can't even THINK of a way to use "could of" which would make linguistic sense, not even if I summon skillz in Old English.