Syntactic Theory

NP Movement

Wh-movement is used to account for the fronting of expressions such as interrogatives. An important property of wh-movement is that the landing site of the moved expression is structurally different from the position of a subject or an object. This means that the landing site for wh-movement is higher in the clause structure than the subject position, i.e. higher than SpecIP. This is shonw in the following example:

a. [_IP Pat read the book]]
b. (I wonder) [ [which book]_i [_IP Pat read t_i] ]

In contrast to this, there is also movement into IP-internal positions, such as the subject position or the direect object position. This can be illustrated best with the passive voice.


Consider the following sentence:

The man considered the idea.

We know that consider is a two place relation that holds between something that is considered and someone who is considering: Consider has two theta-roles and assigns them to two argument. Once passivized, the valency of the verb is reduced to one, as we can see in the following passive sentence:

The idea was considered.

Here, only one argument is realized, namely the internal argument of consider. There is no external argument. The deep-structure representation of the sentence is thus:

[_IP e [was [_VP considered [_NP the idea]]]]

The subject position is empty in this representation, reflecting the fact that the verb does not assign a theta-role to an external argument. The logical object of the sentence is the idea. The fact that this NP is the semantic object of the verb is reflected in its being base-generated in the object position, namely as a complement to the verb. Consider assigns its internal theta-role to the NP at DS. The idea, in turn, is the PATIENT or the EXPERIENCER of the activity denoted by the verb.
Overt NPs require case by the Case-filter. This is why the idea moves to SpecI to receive Nominative Case via government of finite INFL. By moving to SpecI, the NP leaves a trace. The SS-representation of the sentence looks like this:

[_IP [_NP the idea]_i [was [_VP considered t_i]]]