Interrogative CPsWe have seen in a number of previous places that the head and the specifier have a
special relationship. In the IP where the subject sits in the specifier and the agreement
morpheme sits in the head position, the two elements ‘agree’ with each other in terms
of number and person features. Thus if the subject is a third person singular element,
then the agreement will be third person singular and determine that the finite
morpheme ‘s’ will show up on the verb. In the DP, the possessor sits in the specifier
position and this can only be accompanied by a determiner that ‘agrees’ with it in
terms of possession. We might assume therefore that the CP will be no different and
that the head and its specifier will enter into an agreement relationship, presumably in
terms of the [+wh] feature. So, if the specifier has this feature, so will the head. Of
course, if the head has the feature, then it will project it to the CP and this will be
interpreted as an interrogative clause, and hence the wh-specifier can indeed influence
the interpretation of the clause in a round-about manner:
(30) CP
wh C'
C IP
In (30) the double arrow represents the agreement relationship between the head and
its specifier and the single headed arrows represent the projection of the head’s
features to the CP. By this path then the [+wh] on the wh-element ends up on the
whole CP and a CP with a wh-specifier will be interpreted as interrogative. Thus, one
motivation for wh-movement might be that there is need to interpret the clause as an
interrogative.
This cannot be the whole story however. The following indicates that moving the
wh-element to the front of the clause is not obligatory:
(31) A I voted for the Monster Raving Loony Party
B you voted for who?
B’s response involves what is known as an echo question, in which a previously
uttered sentence is more or less repeated and a part of it that was either not heard or
not believed replaced by a wh-element. The meaning is quite clear: it is a request for
someone to repeat or confirm the previous statement. This is very different from the
meaning of a wh-question which is asking for information about a particular aspect of
the sentence. Compare:
(32) a who did you talk to?
b you talked to who?
One major difference in meaning between these two sentences is that the first
presupposes the truth of the proposition: the speaker assumes that you spoke to
someone is true. Thus this kind of question cannot be asked felicitously if the speaker
doesn’t think that you spoke to anyone. This is not true of (32b), however. In repeating
back the previously made statement, the speaker does not commit himself to either its
truth or falsity: judgement about that is postponed until the answer is received. Clearly
this difference in meaning has something to do with where the wh-element is situated.