Language is about communicating. But it is also about attending to perturbations in the air (speech) and marks on pages (writing). These have to make contact with what we have previously learned about language.

One way or another, speaking, listening, reading and writing use a lot of the brain, a lot of the body, and all of the world around us (including other people) in so far as we can refer to anything in that world.

We want to understand how all of this works.