Jonathan knows a new word! I've been using "pat pat" with him to encourage a gentler sort of motion (as opposed to "bang bang", you know!) And today he demonstrated that he understands what I'm saying! He had two blocks in his hand, and was patting them on my leg. I said "you're patting my leg, pat pat", and he grinned and patted them together. This might not seem so neat, except that patting blocks together is what I've been using when I work on the concept with him. Besides, his eyes showed understanding. Does that make sense?
What a brilliant child I have. :)