Overview

Most of our discussion in the previous two chapters has been concerned with providing empirical substantiation for the claim that sentences are hierarchically structured out of constituents belonging to a restricted (perhaps universal) set of categories, and with considering the nature of categories. Implicitly, we postulated a two-level Theory of Categories: that is to say, we tacitly assumed that there are two levels of categories in natural language, namely

1. (1) (i) word-level categories, e.g.

2. N = Noun; V = Verb; A = Adjective; P = Preposition;

3. ADV = Adverb; M = Modal; D = Determiner, etc.

4. (ii) phrase-level categories, e.g.

5. NP = Noun Phrase; VP = Verb Phrase; AP = Adjectival Phrase; PP = Prepositional Phrase; ADVP = Adverbial Phrase, etc.

In this chapter and the next, however, we are going to argue that our existing Theory of Categories should be extended to include a third type of category intermediate between word-level and phrase-level categories. That is to say, we are going to argue in favour of positing that there are nominal constituents larger than the Noun but smaller than a full Noun Phrase, verbal constituents larger than the Verb but smaller than a full Verb Phrase, adjectival constituents larger than the Adjective but smaller than a full Adjectival Phrase … and so on.