This is tremendous. I'm now playing 'genuine typo v whoosh' in my head.A former GF of mine is German. She absolutely loathed what she called 'English Verdplay'. The way we say things that are not quite correct, either for comedy porpoises, or because we aren't particularly bothered about the accuracy of certain things. I sometime look back on a conversation I have had and have thought "I should of done better, there", but in reality ambiguity, whether deliberate or carless, is part of being English.
It has the added benefit of allowing non-English to imagine they understand what's going on when in reality they have been duped, whooshed or simply mocked without their realizing. A childish sport, I realize, but it is quite....moreish.
I have to say it can be a challenge for the neurodiverse (moi) and I guess it can be a source of absolute fury for the non native-speaking neurodiverse (such as my German ex-GF). But on the whole, if there is any one thing that defines Englishness, this is it
The 'should of' is a whoosh for sure as it's at least your second. Maybe your forth*
It's only a matter of time before I do it deliberately, having been brainwashed by whooshes, resulting in my brian** no longer recognising the WRONGNESS.
*what?
**genuinely, WHAT?