We've been working on signing for a long time now. I think I started showing him the sign for milk about 8 months ago, and that was the first one he picked up. He now has a vocabulary of about 6 signs, and we work on new ones all the time. He's slowly getting more consistent with them, and I'm getting better at recognizing them. Here are the ones he uses regularly.
Milk: This one means "nurse" for us, as that's the only kind of milk Carter gets. Since this was his first sign, it seems to have formed the basis of lots of other signs for him, including some he's made up.
Want: This is one Carter made up, but it's remarkably close to the real ASL sign for "want". He points his hand in the direction of what he wants and opens and closes his fist. This is usually directed at the cat, at toys, and at my food or drink. I read somewhere that if babies aren't pointing by this age, that can be a sign of a developmental delay. Carter doesn't point at things with one finger, which could be a sign that something is wrong. But then again, I don't point at things, so why would he? He lets me know what he wants in no uncertain terms, so I'm not really worried. But I will still bring it up to the Early Childhood Intervention counselor at our next meeting, just in case.
Light: This is a new sign, and one he uses ALL the time. He doesn't do the real ASL sign, but approximates it as best he can by opening and closing a fist with just his middle and ring fingers. He signs "light" at every kind of light fixture, from table lamps to chandeliers to fluorescent lights in stores to regular overhead lights around the house. If I say the word "light", he'll look around for one and then sign. If we're in a dark room and I turn a light on, he'll sign "light". Clearly, he gets the concept. It's pretty cool!
All done: This is one I've just figured out. He kept doing this waving thing with two hands (like the royal wave), and I couldn't figure out from the various contexts he used it in quite what it meant. It was clearly meaningful and deliberate, and so I felt bad that I didn't understand him. But then I finally realized he was using that sign for "all done", and it's been interesting to watch him use it. He will use it during mealtime when he's finished eating, and when he signs it, he means it. Tonight we were having blackberries for dessert, which he loves. He ate at least a dozen, and then signed "all done". Just to be sure, I put one more blackberry in front of him, and he ignored it. It sat there for the whole 5 minutes it took me to clean him up, and he never touched it, even though he had gobbled up every blackberry until then.
We went to Gymboree class today, at 12:15 instead of the usual time of 11:15. He was tired, and with about 15 minutes to go, he crawled away from the group area where we were all playing, sat a distance away, and started signing "all done". He was ready to go! He fell asleep in the car on the way home and that led to a 3-hour nap! He also will sign "all done" when he is finished with a task, whether you are or not, like diaper changing. He'll sign "all done" while I'm trying to get a clean diaper on him, wiggling and trying to roll away the whole time. He'll sign it with just one hand if that's all he has free. It's cute that he's trying to express his independence, and it lets me know when he's getting frustrated.
Tree: This is a new sign we've been working on, and I think he gets it, but it's so close to his sign for "all done" that I'm not sure the difference is clear to him yet. He will sign it when we're outside, though, and if I sign and say "tree" he will look up at the closest tree.
Poop: His sitter uses the "potty" sign for poop, and Carter will sign it every now and then. He's not consistent about it, but when he has a poopy diaper sometimes he will let you know by signing "poop". You can ask him if his diaper is poopy, and sometimes he will sign "poop" back to indicate that it is. Sometimes he'll shake his head "no". Other times, he just stares back blankly, so this is one we're still working on!
Other signs we're currently trying to learn are "mommy", "daddy", "play", "in", "out", "ball", "kitty", "more", "bath", "sleep", "hurts", "drink", and "eat". I try to sign those as much as possible, and he'll catch on at some point. I know he understands some of them when I do them; I can sign "kitty", for example, without speaking and he will look for the cat. It's already paying off, even though it's coming along slowly. The fact that he's learning how to communicate with us at all at this age is fantastic. It will probably be another year before he even starts to speak, so I feel like we're getting a head start on communication. :-)