coherent units called PHRASES on which syntactic rules operate. Some simplified phrase structure rules are
shown below.
[4.25]
a. S NP VP
b. NP (Det.) N (PP)
c. VP V (NP) (PP)
d. PP P NP
Notes:
(i) The arrow is to be interpreted as ‘consists of’
(ii) Parentheses indicate that the presence of an item is optional. The rest of the abbreviations are listed on p.
xvii.
Often it is more convenient to show the information conveyed in phrase structure rules using a PHRASE
STRUCTURE TREE. Such trees express more explicitly the ‘hierarchical’ nature of syntactic structure.
Syntactic organisation
is like Chinese boxes, with smaller units contained in bigger units.
The first three phrase structure rules [4.25] can be re-stated as shown in [4.26].
It says in [4.26a] that a sentence contains two constituents, a NP and a VP; [4.26b] says that a NP can
contain a noun on its own or a noun together with either or both a determiner and a PP. In [4.26c] we see
that a VP must contain a verb which may be followed by either a NP or a PP, or both a NP and a PP.
In the dictionary, words are entered with a word-class label like N for noun. Adj. for adjective, V for verb
and P for preposition. A word belonging to the appropriate class is selected to fill a slot below N, V, P etc.
In
other words,
below N we put a noun,
below V we put a verb, and so forth.
We can represent a whole sentence in a tree diagram as shown in [4.27]:
Phrase structure rules and phrase structure trees are not to be seen merely as a statement of the
constituent structure of a given sentence but as very general rules for GENERATING, i.e. enumerating, an
indefinitely large number of sentences with the same structure.
The man makes watches is analogous to
The
girl loves tennis, The chicken lays eggs, The student hates exams
etc. All these sentences and thousands
more are generated by [4.27] if the appropriate words are provided.
At no cost, we can use the rules that produce sentences to produce compound words. Selkirk (1982) has
proposed that in morphology we should characterise the structure of compounds by harnessing the phrase
structure rules used in syntax. The realisation that compound words share important properties with
sentences has important consequences. We can represent the structure of the verbal compounds we have
discussed using phrase structure trees:
To conclude, the fact that deverbal compounding usually operates in a predictable way means that it is not
necessary to list all the compounds in the lexicon and memorise them. Just as it is possible to use phrase
structure rules in syntax to produce an indefinitely large number of sentences, it is also possible, when
dealing with lexical items, to use phrase structure rules in morphology to produce an indefinitely large
number of compound words. Morphology is no different to syntax in the rules it employs for this purpose.
[4.26]
[4.27]
[4.28]
ENGLISH WORDS 53