The third type of usage-based explanation appeals to the flow of information in discourse. Such explanations start from fact that language used to communicate and communication involves the conveying of information. Therefore, it is argued, the nature of information flow should leave and has left its mark on grammatical structure. The great majority of functionalist work takes this idea for granted. Indeed, the tailoring of grammatical structure to the needs of discourse is the core idea of functionalism for many practitioners of that approach.
Now let us consider information flow in discourse. What do we mean by that precisely? We know that there is a general tendency for old information to precede new information. The question is what we need to appeal to in order to explain this tendency. A long tradition sees it as somehow rooted in human nature that order of elements should be first old and then new. For example, Jan Firbas discusses the connection between old information and low degrees of communicative dynamism and new information and high degrees of communicative dynamism and goes on to write: 2b1af7f3a8