Inverse Copular Constructions - Importance For The Theory of Grammar

Importance For The Theory of Grammar

Inverse copular constructions challenge one of the major dogmas of the theory of clause or sentence structure, i.e. that the two basic constituents of a sentence - the noun phrase (NP) and the verb phrase (VP) - are associated with the logical/grammatical functions of subject and predicate (cf. phrase structure rules and sentence). In fact, copular sentences that maintain the canonical groupings are not adequate on empirical grounds, since a very unorthodox left-branching structure is necessary, or if one rejects the canonical groupings and positions the subject inside a VP-like constituent, then one has to assume that the subject NP and copula verb can form a type of VP to the exclusion of the predicative expression. These analyses are illustrated with the following trees:

The tree on the left shows the traditional division of the clause into a subject NP and a predicate VP. Most declarative sentences in English are consistent with this analysis because most sentences allow one to acknowledge the pre-verb NP as the subject. Inverse copular constructions, however, do not readily allow this division precisely because one really cannot group the postposed subject together with the copula so that the two continue to form a VP constituent. If one nevertheless does group them together as shown in the second tree, the resulting structure is very unorthodox because it is left-branching. Or if one nevertheless does position the subject inside a VP-type constituent as shown on the right, this VP-type constituent is problematic, because phrase structure grammars do not generally group the subject together with the copula to the exclusion of the predicative expression.

To remedy a phrase structure analysis of copular sentences, the theory has to augment the analysis with additional assumptions. The standard explanation is to assume movement, whereby the traditional NP-VP division is maintained in a sense, but it exists at an underlying level of structure. One assumes that that both the copula and the predicative expression move out of their canonical positions to positions higher in the tree structure, e.g.

This analysis maintains the binary division of the clause into NP and VP, but at the cost of major stipulation. One has to assume that at least two instances of movement occur; both the subject two of the problems and the copula are move out of their base position up the structure to the left.