DS1 (18months) goes to a nursery where they do baby signing with him. He now does quite a few signs but I'm not sure what the sign is for thank you which I'm pretty sure he's trying to use. He's not in now until next Monday, I forgot to ask the nusery staff and I'd like to reciprocate if he trys to say thank you to me. (as an aside, know I see how useful he finds signing to communicate I wish we'd gone down the road of doing it at home.)
thanks