Chapter 8 - The Syntax of Non-Finite Clausesreplacement of the agentive or experiencer light verb with the passive morpheme
which neither assigns a -role to the subject position nor assigns Case to the specifier
of the VP. Consider what happens when an exceptional verb is passivised:
(17) a the outlaws 1 were expect-ed [t 1 to be in hiding]
b the sheriff 1 was suppose-ed [t 1 to be lost]
c his horse 1 was assume-ed [t 1 to be outside the saloon]
d the horse 1 was understood [t 1 to be brighter than the deputy]
e the sheriff 1 was requir-ed [t 1 to arrest the outlaws]
The subject of the non-finite clause moves to the subject position of the passive
verb just like the object of a passivised verb does. Given that we argued that the
motivation for the object’s movement was to get Case, having been robbed of its light
verb Case assigner, it is reasonable to assume that this is exactly what is going on with
the movement of the subject of the exceptional clause.
Let us take a look at this analysis in more detail. Suppose we take a structure
similar to (12) and replace the light verb with the passive morpheme:
(18) vP
v'
v VP
believe 1 -e IP V'
DP I' V
him I vP t 1
v'
v VP
to be on their trail
The two immediate consequences of this are that the experiencer -role fails to be
assigned, leaving the specifier position of the vP empty, and the subject of the
exceptional clause is left without Case given our assumption that the passive
morpheme is not a Case assigner and neither is the non-finite inflection. Thus if the
subject were to stay in this position, it would violate the Case Filter, which demands
all DPs to receive Case, and hence the sentence would be ungrammatical, which it is:
(19) *it was believed [him to be on their trail]
Note that if the complement clause were finite, there would be no problem:
(20) it was believed [that he was on their trail]