Luke's new "word"

Just today Luke started saying, "Yeah" instead of just saying "Uh Huh" when he is answering an affirmative. It's very cute..."Luke do you want that?", "Yeah". It'd be nice if he'd say, "Yes Mommy", and if you tell him to he WILL say, "Yes Mommy Dearest", but it's not his natural response. For now I guess I'll have to be happy with a simple, "Yeah".