Chapter 3 - Basic Concepts of Syntactic TheoryIf the VP cannot be argued to function as a clause, one might try to argue that
clauses and subjects have certain things in common. For example, a clause can act as a
subject:
(17) [that ice cream production has again slumped] is bad news for the jelly industry
But this does not show that subjects are functional equivalent to clauses but quite the
opposite: clauses may be functionally equivalent to subjects under certain
circumstances.
Therefore it would appear that clauses are exocentric constructions, having no
heads, and as such stand outside of the X-bar system. Later in this book, we will
challenge this traditional conclusion and claim that clauses do indeed have heads,
though the head is neither the subject nor the VP. From this perspective, X-bar theory
is a completely general theory applying to all constructions of the language and given
that X-bar theory consists of just three rules it does indeed seem that I-language
principles are a lot simpler than observation of E-language phenomena would tend to
suggest.
1.3 Heads and Complements
But if the structural rules of the grammar are themselves so general as to not make
reference to categories how do categorial features come to be in structures? One would
have thought that if all the grammar is constructed from are rules that tell us how
phrases are shaped in general, then there should only be one kind of phrase: an XP.
To see how categorial information gets into structure we must look more closely at
heads and the notion of projection. We have seen how heads project their properties to
the X' and thence to XP, the question we must ask therefore is where do heads get their
properties from? The main point to realise is that the head is a word position and
words are inserted into head positions from the lexicon. In chapter 1 we spent quite
some time reviewing the lexical properties of words, including their categorial
properties. These, we concluded, are specified for every lexical item in terms of
categorial features ([±F, ±N, ±V]). If we now propose that a head’s categorial features
are projected from the lexical element that occupies the head position we can see that
phrases of different categories are the result of different lexical elements being inserted
into head positions.
One way to envisage this is to think of X-bar rules as building a general X-bar
structure devoid of categorial properties. So we might start with the following:
(18) XP
YP X'
X YP
We then populate this structure by inserting words into it from the lexicon and
these bring along with them their categorial features. Suppose we insert the verb fall
into the head position, as this is categorised [–F, –N, +V] (i.e. verb) these will project
to the head position: