Basic English Syntax with Exercises

morphological case

3.2.2.2 S-structure and Case Theory

One way to view this situation is to separate two notions of Case. One notion of Case, relating to the traditional view, is that Case has to do with the form a nominal element takes dependent on its position or, in some languages, its function in a sentence. We can call this phenomenon Morphological case. The other view of Case is that this is something a DP gets simply by occupying a certain structural position, whether or not it is realised overtly. We call this Abstract Case, or just Case (spelled with a capital). From this perspective then, any DP that occupies the subject position of a finite clause has nominative Case irrespective of whether that DP looks different from what it would if it were sitting in an object position and bearing accusative Case.

3.2.2.2 S-structure and Case Theory

But why would any of this mean that the sentence should be ungrammatical? Only with an extra assumption can we account for this properly: the pronoun subject needs a Case. One might think that this is fairly obvious as there is no Case neutral form of the pronoun: what form would it take if it occupied a Caseless position? However, the following observations seriously question the assumption that the ungrammaticalities in (87) have anything to do with Morphological case:

3.2.2.2 S-structure and Case Theory

What we see here is that even a nominal element that does not display morphological case distinctions cannot occupy a position to which no Case is assigned. Thus the requirement that a nominal element have Case is nothing to do with the impossibility of the choice of morphological form when no Case is assigned. Instead, it appears to be a general requirement that all DPs must occupy a Case position. We call this requirement the Case Filter:

3.2.2.2 S-structure and Case Theory

The fact that the Case Filter applies to all DPs and not just those that demonstrate morphological case is strong evidence in favour of the assumption of Abstract Case.