It led to an interesting thread 
, but only one is correct.
Certainly I’m not talking about speech impediments, nor accents or use of slang.
Coming from Norf Lunn’n, I ain’t aving it any uvver way!
What glee was saying was that when pronounced with a British accent, the word ‘of’ has a distinct short ‘o’, as in ‘shot’, rather than the ‘uh’ sound (often represented phonetically as the schwa, or upside-down ‘e’) that Americans use in the word ‘of’. Presumably, having a speech impediment that involves using a short ‘o’ in place of a schwa would have been noticed before one “could’ve” vs. “could of” incident. Of course, I’m giving glee the benefit of the doubt and assuming that he’s a competent teacher, but since he’s a Doper, I think he’s worth it.
And when someone does this, I’m not convinced that she is actually clear on what it is she’s saying. I wonder how she’d spell what she’d just uttered. Frankly, I doubt that she would spell “I should HAVE done this last night.” I imagine that she would spell exactly what you wrote: “I should of done this last night.” I taught for many years and am convinced that many young people have not given much thought to that particular construction, nor to many other idioms they use, and for that reason, would be hard pressed to describe, explain, or much less spell the phrase we are discussing.
That’s how I imagine she would have written it, too, to tell you the truth.
Thanks, waterj2, for clarifying what I was saying. You’re correct: I was merely demonstrating how, in my accent, one can clearly say “should of.”
Heh. I have a London-based friend for whom the saying “You can’t say fairer than that” is literally true… “fairer van vat” would be his best approximation.
Another vote for the observation that Pterry is always grammatical but his characters aren’t necessarily. It used to tick me off when my teachers dinged me for putting bad grammar in reported speech, when it was a deliberate literary device.