When I talk about AAC systems I talk about robust language systems. By that I mean a Communication system which will enable you to have access to all the words that you might need, and to communicate for all the reasons that human beings communicate. That might, just might, include being told something really cheeky. And at Christmas we need access not only to words that let us say "happy Christmas" and "thank you", but also to grumble, nag and bicker.