form of a coordination of clauses (or a ‘clause-coordination’).1 Within this framework,
the clause is a more basic unit than the sentence.
To say that sentence [1i] has the form of a clause is not to say that it consists of
a clause, as the term ‘consists of’ is used in constituent structure analysis of the type
introduced in Ch. 1, §4.2. There is no basis for postulating any singulary branching here,
with the clause functioning as head of the sentence. This is why our tree diagram for the
example A bird hit the car had the topmost unit labelled ‘clause’, not ‘sentence’. ‘Sentence’
is not a syntactic category term comparable to ‘clause’, ‘noun phrase’, ‘verb phrase’, etc.,
and does not figure in our constituent structure representations.
Most work in formal grammar makes the opposite choice and uses sentence
(abbreviated S) rather than clause in constituent structure representations. There are
two reasons why we do not follow this practice. In the first place, it creates problems for
the treatment of coordination. In [1iii], for example, not only the whole coordination but
also the two clauses (Jill seems quite friendly and but her husband is extremely shy) would
be assigned to the category sentence. The coordination, however, is quite different in its
structure from that of the clauses: the latter are subject–predicate constructions, while
the coordination clearly is not. Most importantly, assigning the whole coordination to
the same category as its coordinate parts does not work in those cases where there is
coordination of different categories, as in:
[2]
You must find out [the cost and whether you can pay by credit card].
Here the first coordinate, the cost, is an NP while the second is, on the analysis under
consideration, a sentence, but the whole cannot belong to either of these categories.
We argue, therefore, that coordinative constructions need to be assigned to different
categories than their coordinate parts. Thus we will say, for example, that Jill seems quite
friendly is a clause, while [1iii] is a clause-coordination, Jill and her husband an NP-
coordination, and the bracketed part of [2] an NP/clause-coordination (a coordination
of an NP and a clause).
The second reason why we prefer not to use ‘sentence’ as the term for the syntactic
category that appears in constituent structure representations is that it involves an un-
necessary conflict with the ordinary, non-technical sense of the term (as reflected, for
example, in dictionary definitions). Consider:
[3]
a. The knife I used was extremely sharp.
b. I’m keen for it to be sold.
The underlined sequences are not sentences in the familiar sense of the term that we
adopted above, according to which sentences are units of a certain kind which occur
in succession in a text. The underlined expressions nevertheless contain a subject (I, it)
and a predicate (used and to be sold), and hence belong in the same syntactic category
as expressions like Jill seems quite friendly. If we call this category ‘sentence’ rather than
‘clause’, the term ‘sentence’ will have two quite different senses.