They are just busting out. In the last five days we’ve heard:

airplane—We were putting the garbage out, and David looked up into the blue sky, and told us what was there.

triangle (the musical instrument, not the shape)—ding ding!

play—Oh you want OUT of your chair. You want to go PLAY?

up—I don’t why he bothers with this one. His body language makes it infinitely clear.

big—That ball is too BIG to go in that hole. UH OH.