You say he doesn't like to talk. Does he like to read? Start with picture books (mice might be a good topic but chicken or fish would also work) and reward him for each page he completes. You could write a personal note on each page to see if he's paying attention.

You should probably wait to start the lesson until he has been awake for 10 minutes, if this is possible. I'm assuming he stays awake that long at least once in a while.