ABSTRACT
Relational Grammar (RG) was developed primarily by David Perlmutter and Paul Postal in the early 1970s. In this theory grammatical relations are taken to be undefined primitives. The set of relations recognized includes subject, direct object, indirect object, and an as yet undetermined number of oblique relations including benefactive, locative, and instrumental. The three relations subject, object, and indirect object are collectively called terms. These and the obliques form a hierarchy as in [1]:
[1] subject direct object indirect object obliques 1 2 3
The terms are conventionally referred to by their position in the hierarchy, so a subject is referred to as 1, a direct object as 2, and an indirect object as 3. 1 and 2 are known collectively as nuclear relations and 2 and 3 as object relations.
