Basic English Grammar with Exercises

Interrogative CPs

But this is a puzzle. Why do we not get inversion in an embedded interrogative? If
the account of why we get inversion in main clauses is as we have so far suggested,
then we must conclude that the question complementiser either does not need binding
in an embedded clause, or that it is bound by some other element. For example, we
might assume that the question complementiser in an embedded clause is not the same
complementiser that appears in the main clause. We know that we do not get the kinds
of overt complementisers that introduce embedded clauses in main clauses:

(50) a that Rachel is rich
b if you saw that

However, we have also claimed that main clauses are CPs and so have
complementisers introducing them. Therefore there seems to be a distinction between
main clause and embedded clause complementisers. If this is so, then we might claim
that the main clause interrogative complementiser differs from the embedded
interrogative clause complementiser in that the former is a bound morpheme while the
latter is not:

(51) a CP b V'

wh C' V CP

C IP wh C'

-Q DP I' C IP

I VP Q DP I'

aux I VP

aux

But this is a rather ad hoc solution which doesn’t really tell us why things are this
way and hence does not really have much by way of explanatory content.
A second proposal claims that the difference between main and embedded clauses
is that while complementisers are allowed in embedded clauses they are not in main
clauses. Thus, a main clause interrogative actually lacks an interrogative in the C
position, which is therefore underlyingly empty. An embedded clause on the other
hand differs in two ways from a main clause: complementisers are allowed in
embedded clauses and the clause itself is selected as a complement by some predicate.
We have seen how a predicate imposes selectional restrictions on its clausal
complements and those predicates which take an interrogative complement will
demand that the CP be marked as interrogative. The way to mark a clause as
interrogative is to give it an interrogative head and this can either be overt, i.e. if or
covert, i.e. Q:

(52) a Robin doesn’t remember [CP if [IP she bought bread]]
b Richard doesn’t recall [CP where Q [IP he left his horse]]