Caleb constantly cracks us up with his expressions.
"I, too!" - for some reason he has adopted this expression in lieu of the more common "me too!"
"I do!" - when he hears something he wants, he lets us know he wants to be included.
"Yaah" - a drawn out, very Russian sounding "yes".
"No" - okay, this isn't original, but the firm, matter of fact way he has of saying it makes us laugh. It is part defiant and part laissez-faire. No is the answer and he's not going to fight with you.