I was lucky enough I supose you would say to have been through it already with my first son who is now 4 so when my youngest 23months decided he didn't want his nappy on any more we took his favourite teddy and put a nappy oon him  and tok teddy to potty and as much as some people dont like the idea of taking child with you to the toilet he was very curious what was happening and I got him to sit on the potty when we were in the toilet, either my husband or my self. He has now taken a lot more interest in it and goes and gets the potty himself. As for the communication side of things, does he listen to you if you ask him to do something, if he does then he at least has some understanding of what you are saying and from there you just need to feel your way through the rest. He will do it when he is ready and unfortunately not before. Good luck.