ABSTRACT
This article is best read in conjunction with the article on SCALE AND CATEGORY GRAMMAR. In systemic grammar, the notion of the system, as used in M.A.K.Halliday’s earlier model, is no longer seen as a single set of choices available at a particular place in structure; now (Butler, 1985, p. 40):
we find the paradigmatic patterning of language described in terms of sets of systems, or system ‘networks’, operating with a particular rank of unit, and sometimes a particular class of a given rank, as their ‘point of origin’. Certain system networks are selected from a clause rank, others operate at the nominal class of the unit group, and so on.
