Well, not quite.
For some time, he has been capable of question and answer in the following sense. I ask a question like? “Do you want to go for a ride on the motorbike?” and he will grunt back in the affirmative. Not exactly the Queen’s English, but still communication complete with understanding, despite the caveman-like quality of it
I am now beginning to detect attempts to create separate words for different responses. Still not consistent enough in his articlation for me to be sure that he is truly searching for a particular word. But if I had to put money on it, I would guess that he is.
He also does the following thing which I think is so cute. When he is misbehaving in some way and we tell him to stop, we raise a hand in a gesture that we are going to hit him and ask “เอา ไหม?” (“Ao mai?”, “Do you want this?”) and he will shake his head strongly.