Role and reference grammar (RRG, Van Valin 1993)may be termed a ‘structural-functionalist theory of grammar’, rather than purely formalist or purely functionalist, as 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. Language is considered here 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.