Great stuff that he's improving so well so fast!
While he can't talk, you might want to think about flash cards (images and words) for common things that John may want, eg, a pic of you, a pic of your children, a pic of a nurse, a pic symbolising pain, just so that it's not so frustrating for him trying to communicate (someone that I'm very close to used such flashcards when he had a trackie in, I think he had both cards and 2 or 3 sheets of A4 paper with them all on too, made things alot easier for him at the time). xx