Can you elaborate on this: You couldn't've known it

Hi folks…
Can you elaborate on this: “you couldn’t’ve known it”. So, I am quite sure that in the written part it is not ok, nevertheless, I’ve heard people saying it…Then, is that ok when pronouncing it?

Thanks a lot!

.
couldn’t’ve
shouldn’t’ve
wouldn’t’ve
won’t’ve

You’re right, Serzige. Contractions such as the ones above are all quite normal in spoken English. :wink:

Amy