Clock without the "L"
Rock stats with a "C" not an R
Thank you sounds like "f*** you" but I think he's saying "funk"

We used to have
"up a gup" for up you get.
"mobike" for motorbike
Banana has gone from "bananana" to "banana" to "bana". Now it's banana again.

I know there heaps more but I can't think of them...

ETA - we have a lift-the-flap book called Peek-a-boo Peter, that DS has memorised.
One page says:
"I see a smart red coat, can you see it too?
Peter Rabbit, Peter Rabbit, is that you?
That's not Peter, that's Jeremy Fisher!"

DS says:
"I see a smart red coat, can you se it too?
Peter Rabbit, Peter Rabbit, is that you?
That's not Peter, that's Jemima Fishycat!"