Although this 19 month old doesn't say hardly anything, he knows a few words in sign language. More, hi, bye bye, please, thank you, and all done. In this video he actually says "all done". I don't think I've heard him say it before. I did hear him say bye bye one time, but only once. He understands lots of directions like putting stuff in the trash for us and picking things up off the floor. He knows it's time to leave when we say go or bye. He puts a hand to his ear like a phone for hello. And he sticks his tongue out when he tries to say Ayla's name.