How has this mistake come about and why is it now so widespread that a reasonably well-educated person can write it?
It comes from spoken language. "Could have," "would have" and "should have" are all elided to "could've," "would've" and "should've" in speech. And, because they sound almost indistinguishable from "could of," would of" and "should of" that's what they have become in writing.
Can you imagine Eliza Dolittle singing "I could of danced all night"?
Sat and stood
A university teacher friend asked on Facebook today asked if she must now accept "he was sat" and "she was stood" in students' writing. It's a dialect form from the north of England, which is beginning to replace "he was standing" and "she was sitting" in Standard English. Why?
"Stood" and "sat" are past participles of the verbs "stand" and "sit." "Standing" and "sitting" are present participles. My theory is that in their determination to express a past action, the user of this form doesn't want to rely on the little word "was" but needs to emphasise the timing of the action by putting the participle into a past form too.
|Photo Blanche Morin|