Chapter 5 - Verb Phrasesrequirement between the two is a reflex of X-bar theory itself: the head must be
adjacent to its complement otherwise an ill formed structure results:
(171) XP
X'
X'
X adjunct complement
If an adjunct is placed between the head and its sister, i.e. the complement, the branches
of the structure cross and this is not a possible configuration. The problem with this
account, however, besides its reliance on the assumption that complements are all sisters
to the head, is that it is not at all clear why various movement phenomena would not
separate the head from its complement. Another account, due to Stowell (1981) assumes
that the verb is responsible for assigning Case to the object and that there is an
adjacency requirement on Case assigners and assignees. As we have assumed that the
theme gets its Case from the light verb, we cannot use Case adjacency to account for
why the verb and its theme argument cannot be separated. Even if we assume that Case
assigners must be adjacent to the element they Case mark, this will not prevent the verb
moving to a higher light verb position allowing an adverb to come between the two:
(172) vP
DP v'
v vP
AP vP
v'
v VP
DP V'
V
This structure has the adverb phrase adjoined to the lower vP and the verb moving to
the higher light verb. Such a structure would be possible either when there is both an
agent and an experiencer argument, or if the top light verb is an aspectual morpheme.
The structure that would be produced however would be ungrammatical as the adverb
would appear between the verb and its theme argument.
We might try to account for this restriction by limiting the kinds of structure that
the adverb can adjoin to. But this seems unlikely as under certain conditions adverbs
appear to be able to adjoin to virtually any part of the VP: