1.3 A Typology of Word Categories

Having introduced some of the basic concepts, let us now turn to look at what categories we need to refer to in the description of a language like English. In generative linguistics it is often seen as a positive aim to keep basic theoretical equipment to a bare minimum and not to expand these unnecessarily. This can be seen in the standard approach to word categories in terms of the attempt to keep these to as small a number as possible. In the present book we will mainly be concerned with eight basic categories. These come in two general types: thematic categories and functional categories. In the thematic categories we have verbs (V), nouns (N), adjectives (A) and prepositions (P) and in the functional categories there are inflections (I), determiners (D), degree adverbs (Deg) and complementisers (C). Thus we have the following classification system:

1.3.1 Categorial features

Before we start to look at the properties of individual categories, we will make the typology of categories described in (23) a little more systematic. One might wonder why there are these categories and why their division is so regular: four thematic categories and four functional ones. Moreover, we may have the feeling that the categories given in (23) are not completely unrelated to each other. For example, it is often felt that nouns and verbs are somehow opposites of each other or that adjectives have some things in common with nouns and other things in common with verbs. Even across the thematic/functional divide, we may see similarities. For example, words like the, these and some are determiners and these seem more related to nouns, which they usually accompany, than to verbs. Modal auxiliary verbs, such as may, can and must, which as we will see are classified as belonging to the inflections, are obviously more closely related to verbs than nouns.

1.3.1 Categorial features

One way to impose a system on elements is to use a set of features to distinguish between them. Each category can then be defined in terms of a unique collection of these features, but they may share some of the features with other categories, accounting for similarities between them. In linguistics, binary features, i.e. those which can be valued in one of two ways (plus or minus), have been found useful for producing systems of categorisation. For example, we might propose a feature [±F] (‘F’ to indicate functional) to distinguish between the thematic and functional categories. All thematic categories would possess the [–F] feature and all functional categories would possess the [+F] feature. In this way we can immediately distinguish between the two groups and account for why certain categories are similar to others in terms of which feature they possess.

1.3.1 Categorial features

In other words, determiners are the functional equivalents to nouns and modals are functional verbs.

1.3.1 Categorial features

We see from the discussion above the predictive power of the system that we have set up: the system predicted that there should be a fourth thematic category that has certain properties and these fit the category of prepositions very well. We can take this as evidence in favour of this system of features. What else does the system predict? It is clearly predicted that if we add a third binary feature to the two we have just been discussing, then a further four categories will be defined. This again matches perfectly with the description of categories we started this section with, as seen in (23). With the third feature, [±F], there should be four functional categories which match the four thematic categories in terms of their feature settings for [±N] and [±V]. We have already seen how determiners and modals can be analysed as functional nouns and functional verbs, respectively. The expectation is that degree adverbs, such as so and too, and complementisers, such as that and if, should be related to adjectives and prepositions in the same way. As degree adverbs modify adjectives in a very similar way to how determiners modify nouns, it is not difficult to conclude that degree adverbs are functional adjectives. This leaves complementisers to fill the final place as functional prepositions. There is evidence in favour of this assumption, but it rests on notions not yet introduced, so we will have to wait until later to demonstrate it.

1.3.1 Categorial features

Another way to extend the system, which we will be making some use of, relies on the notion of underspecification of features. All the categories discussed above are fully specified for all the features, so each is associated with a plus or minus value for all three features. Underspecification is a situation in which one or more features is not specified for its value. Thus, we might propose a new category [+N, –V] which is not specified for the [±F] feature. This category would then be a noun which is neither functional, nor thematic. We will see that there is evidence that the [±F] feature can be left underspecified and hence there are a further four ‘non-functional’ categories. We will introduce these categories in the following sections. The important point for the moment is that the system of features restricts our ability to invent new categories ‘willy-nilly’.

1.3.2 Predicates and arguments

To understand the difference between thematic and functional categories we first need to introduce concepts to do with how the elements of a sentence can be related to each other. Take a simple sentence:

1.3.4 The Thematic categories

Let us focus our attention first on the thematic ([–F]) categories, returning to the functional ([+F]) categories towards the end of the chapter. Much of our discussion so far has concerned verbs. This perhaps reflects their centrality in many sentences, being typical predicates. It also seems that notions such as predicate and argument are more obviously expressed in relation to verbs. So it is right to start our discussion of categories with them.

1.3.4.4 Prepositions

It is possible that, given the complementary distribution between words like that and since, they are of the same category and hence since is not used as a preposition in (130b). Indeed, we will see, words like that, being complementisers, are analysed as ‘functional prepositions’, given their feature specification [+F, –N, –V]. However, we will not pursue the issue here.

1.3.5 Functional Categories

4.2.1 Determiners and Complements

Determiners are rather boring in this respect and it seems that there are no other possibilities. This, as it turns out is very typical of functional categories as a whole, as they all have very limited complement taking abilities. However, even if the range of complements of the determiner is very limited, the arrangement of the determiner and its NP complement still conforms to the general pattern of head–complement relationships in English with the head preceding the complement:

4.4 Conclusion

In this chapter we have introduced the structure of the DP, the projection of a functional category. We will contrast this in the next chapter with the VP, which is obviously the projection of a thematic category. As far as the X-bar structure is concerned, the two are very similar. But, as we know, lexical properties have a very strong influence on structure and hence we might expect that the phrases headed by functional and thematic heads will differ to some extent.

4.4 Conclusion

In this chapter we have introduced the structure of the DP, the projection of a functional category. We will contrast this in the next chapter with the VP, which is obviously the projection of a thematic category. As far as the X-bar structure is concerned, the two are very similar. But, as we know, lexical properties have a very strong influence on structure and hence we might expect that the phrases headed by functional and thematic heads will differ to some extent.

7.5.3 Negative fronting

What is the nature of XP and how does it interact with the other movements we have reviewed? If we are to maintain our view that functional categories select for a very limited selection of complements, then as XP is the complement of a complementiser this argues that it is something like an IP. However, presumably X is a functional element itself and it takes an IP complement, which makes it more like a complementiser. Given that complementisers are categorised as [+F, –N, –V] and inflections are [+F, –N, +V] categories, a category which shares properties of them both would be [+F, –N], with an undefined V feature. Let us refer to this category a little ‘i’, reflecting the use of ‘v’ to represent a verbal element with an undefined F feature. This element heads an iP and so the structure can be represented as: