Aspectual Auxiliary Verbs(158) a did you see that?
b I didn’t see that
c you DID see that!
d you saw that, didn’t you?
In these examples, the auxiliary do adds very little to the meaning of the sentence,
apart from the fact that it carries tense. However, given that main verbs can do this,
this is clearly not the main function of the auxiliary in these examples. Instead the
auxiliary is used to do something that main verbs cannot do. In (158a), the auxiliary is
moved to the front of the clause to form a question, in (158b) it is used to bear the
contracted negative, in (158c) it bears stress in order to assert something that had
previously been denied and in (158d) it is used to form a tag question, the main
function of which is to lessen the force of a statement. As the following show, these
are all things that we cannot use a main verb to do:
(159) a saw you that?
b you sawn’t that
c you SAW that
d *you saw that, sawn’t you?
The ungrammaticality of most of the sentences in (159) shows that the main verb
cannot be used in this way. That (159c) is not ungrammatical does not indicate that it
is an exception, however, as this has a different meaning to (158c). In (159c), the
emphasised verb is used to question or contradict a previous statement in terms of the
content of the verb itself. So, for example, if someone claimed to have seen something
that was invisible to others, (159c) might be an appropriate response. Importantly,
(159c) could not be used to contradict someone’s claim that they did not see
something, i.e. contradicting the truth of their statement. The point is, then, that the
auxiliary do is inserted into a sentence to do something that is impossible for a main
verb to do and hence it has a purely syntactic role rather than a semantic one. For this
reason it is often called the dummy auxiliary. Perhaps its main function is to support
the tense morpheme when, for whatever reason, this cannot appear on the main verb
and hence the phenomenon is also called do-support.
Another instance of the use of a meaningless element might be the use of the
copula be in examples such as the following:
(160) a Tim is tall
b Ferdinand is a fake
c Gertrude is in the garden
Considering the semantic relationships that exist in these sentences, we notice that they
are established between the subject and the predicative element after the verb: Tim and
tall, Ferdinand and a fake and Gertrude and in the garden. Again, the main function of
the verb here appears to be to support the tense morpheme and it seems to make very
little contribution of its own. Indeed, in circumstances where there is no need to
express the tense morpheme, the verb is not used: