[larrymcp]

I think you probably mean "shouldn't have". There is no "shouldn't of".

[rimunroe]

Which gives you an opening for the excellent double contraction “shouldn’t’ve”

[theoreticalmal]

My favorite variation of this is “oughtn’t to’ve”

[b112]

The letter H deserves better.

[mananaysiempre]

The funniest part is that in that contraction the first apostrophe does denote the elision of a vowel, but the second one doesn’t, the vowel is still there! So you end up with something like [nʔəv], much like as if you had—hold the rotten vegetables, please—“shouldn’t of” followed by a vowel.

Really, it’s funny watching from the outside and waiting for English to finally stop holding it in and get itself some sort of spelling reform to meaningfully move in a phonetic direction. My amateur impression, though, is that mandatory secondary education has made “correct” spelling such a strong social marker that everybody (not just English-speaking countries) is essentially stuck with whatever they have at the moment. In which case, my condolences to English speakers, your history really did work out in an unfortunate way.

[knicholes]

I care.

[amanaplanacanal]

That used to be the case, but "shouldn't of" is definitely becoming more popular, even if it seems wrong. Languages change before our eyes :)

[DecentShoes]

Who cares?