Case in GB theory

GB (Government and Binding) theory proposes the following `case filter' as a requirement on S-structure.^4.4

CASE FILTER Every overt NP must be assigned abstract case. [#!haegeman91!#]

Abstract case is taken to be universal. Languages with rich morphological case marking, such as Latin, and languages with very limited morphological case marking, like English, are all presumed to have full systems of abstract case that differ only in the extent of morphological realization. In GB, abstract case is argued to be assigned to NP's by various case assigners, namely verbs, prepositions, and INFL. Verbs and prepositions are said to assign accusative case to NP's that they govern, and INFL assigns nominative case to NP's that it governs. These governing categories are constrained as to where they can assign case by means of `barriers' based on `minimality conditions', although these are relaxed in `exceptional case marking' situations. The details of the GB analysis are beyond the scope of this technical report, but see [#!chomsky86!#] for the original analysis or [#!haegeman91!#] for an overview. Let it suffice for us to say that the notion of abstract case and the case filter are useful in accounting for a number of phenomena including the distribution of nominative and accusative case, and the distribution of overt NP's and empty categories (such as PRO).