From the introduction: "Role and Reference Grammar [RRG] (Van Valin 1993a) may be termed a "structural-functionalist theory of grammar"; this locates it on a range of perspectives from extreme formalist at one end to radical functionalist at the other. RRG falls between these two extremes, differing markedly from each. In contrast to the extreme formalist view, RRG views language as a system of communicative social action, and consequently, analyzing the communicative functions of morphosyntactic structures has a vital role in grammatical description and theory from this perspective. Language is a system, and grammar is a system in the traditional structuralist sense; what differentiates the RRG conception of grammar from the standard formalist one is the view that grammatical structure can only be understood and explained with reference to its semantic and communicative functions. Syntax is not autonomous; rather it is viewed as relatively motivated by semantic and pragmatic factors. In terms of the abstract paradigmatic and syntagmatic relations that define a structural system, RRG deals not only with relations of cooccurrence and combination in strictly formal terms but also with semantic and pragmatic cooccurrence and combinatory relations. Hence RRG may be properly designated as a structural-functionalist theory, rather than purely formalist or purely functionalist."
Van Valin, Robert D. Jr.
"Role and Reference Grammar,"
Work Papers of the Summer Institute of Linguistics, University of North Dakota Session: Vol. 37, Article 5.
Available at: https://commons.und.edu/sil-work-papers/vol37/iss1/5