Structurehead of phrases such as the postwoman is the determiner and the head of phrases such
as on his birthday is the preposition. Thus, we distinguish between determiner
phrases (DPs) and preposition phrases (PPs).
There are also other phrases associated with the verb (VPs), with adjectives (APs)
and indeed with every kind of word category that we have discussed (noun phrases –
NPs, inflectional phrases – IPs, CPs and degree adverb phrases – DegPs).
For now, the main point is that there are different kinds of phrases and these have
different positions within the structure of the sentence and hence different
distributions. We might therefore represent the sentence in (31) more fully as:
(34) S
DP VP
the postwoman pestered DP PP
the doctor on DP
his birthday
We will not develop this any further at this point, and we will see that certain aspects
of this structure are in need of revision. But the arguments for these developments will
be given in subsequent chapters.
1.7 Rules
The last thing we will mention in this section concerns the kinds of grammatical rules
that could be responsible for producing structures such as in (34). Recall from the start
of this section we introduced a formal rule which stated that sentences can be made up
of words and other sentences:
(35) sentence Æ word, sentence
The rule states that a sentence is made up of some words and some sentences.
Although this rule is not particularly accurate, we can see that this kind of rule is ideal
for describing the kinds of structures we have been discussing, as they state what the
immediate constituents of a structure are: in other words, this rule describes mother–
daughter relationships.
From the structure in (34) it is possible to formulate the following rules:
(36) S Æ DP VP
VP Æ V DP PP
PP Æ P DP
DP Æ D N
Such rules are known as rewrite rules as they describe how to draw a tree by ‘re-
writing’ the symbol on the left of the arrow for the symbols on the right. Thus, if we
start with the S at the top of the tree diagram we can rewrite this as a DP and a VP.
The VP can be re-written as a verb, a DP and a PP and the PP as a preposition and a
DP. The DPs can then be re-written as determiners followed by nouns.