He signs "dog" for our neighborhood dog, and has made up his own for "all done" as well as "car." Well, "all done" and "car" are actually the same sign, a big sweeping motion, but I know what he means. I guess he just doesn't have the fine motor skill down!
Still no other words than "ba-la" for balloon, though, and we're at 13 months. I'm not concerned, he knows what he's talking about!