Shouldn't've

[MotleyCroup]

Is this correct to use?

I have to admit I've always written shouldn't have or should've but I've never combined them.

DS was tought this yesterday (Y2) and it stumped me.

I would have taught it to show how should of came about and why it's wrong.

I don't think you can have a double contraction in a single word like that. Even in dialogue I would think it would be "shouldn't 've". I think it's actually something you could reasonable raise with the teacher and ask her to explain what she said about it as you're not clear on what the rules are and you'd like to help DS understand better.

I've seen it before, I think it's right.

I had a £1 bet with DS this morning that the Titanic wasn't built in Liverpool, as he had been taught in school. I'm going to try the same £1 bet with every member of his class - I'll be quids in!

grammar.wikia.com/wiki/List_of_contractions