Verb Types(78) vP
DP v'
Pete v VP
e DP V'
the letter V
posted
If the light verb ceased to be there, both the agent -role and the accusative Case
would be lost in one step. What would be left is the main verb with its patient
argument which would lack Case and hence have to move to subject position:
(79) VP
DP V'
the letter V
posted
Thus, if we analyse the passive construction as involving the loss of the light verb, we
readily account for its two most salient properties.
We might extend this analysis to take into consideration other aspects of the
passive construction. It has been argued that one of the central aspects of the passive is
the appearance of the passive morpheme. The passive morpheme appears in all English
passives, no matter what else happens. Thus, not all passives involve an object moving
to subject position (80a), and while some passives contain a by phrase reintroducing
the missing subject, not all do (80b). Furthermore, most passive constructions involve
a passive auxiliary be, but not all (80c):
(80) a it is expected that Pete will post the letter
b the letter will be posted (by Pete)
c I will expect [the letter posted by noon at the latest]
In all these examples however, the passive verb has the passive morpheme. We can
incorporate this into our analysis of the passive making use of an idea presented above,
that certain bound morphemes can be analysed as light verbs. Suppose we assume that
the passive morpheme is a light verb which replaces the agentive light verb of the
active. As the passive light verb does not assign a -role to its subject, it will not be
able to assign a Case to the theme in the specifier of the VP and hence this argument
will have to move to subject position. Moreover, the bound morpheme status of the
passive light verb will force the main verb to move in order to support it:
agentaccusative