In linguistics, relational grammar (RG) is a syntactic theory which argues that primitive grammatical relations provide the ideal means to state syntactic rules in universal terms. Relational grammar began as an alternative to transformational grammar.

Grammatical relations hierarchy

In relational grammar, constituents that serve as the arguments to predicates are numbered in what is called the grammatical relations (GR) hierarchy. This numbering system corresponds loosely to the notions of subject, direct object and indirect object. The numbering scheme is subject → (1), direct object → (2) and indirect object → (3). Other constituents (such as oblique, genitive, and object of comparative) are called nonterms (N). The predicate is marked (P). According to Geoffrey K. Pullum (1977), the GR hierarchy directly corresponds to the accessibility hierarchy: A schematic representation of a clause in this formalism might look like:

Other features

Universals

One of the components of RG theory is a set of linguistic universals stated in terms of the numbered roles presented above. Such a universal is the stratal uniqueness law, which states that there can be at most one 1, 2, and 3 per stratum. Pullum (1977) lists three more universals: However, Pullum formulated these universals before the discovery of languages with object-initial word order. After the discovery of such languages, he retracted his prior statements.

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