Theoretical Aspects of MovementThere is one more point we need to make in connection with positions involved in
movement. Above we said that the landing site for a moved object in a passive
structure is an empty position: the subject. This seems to make sense given that the
subject position is an integral part of the sentence, without which we would not have a
complete sentence. However, it is not always easy to identify a landing site as
something that exists before the movement takes place. For example, consider the case
of PP preposing, in which a PP is moved to the front of the clause:
(100) a Petra put the book [PP on the shelf]
b [PP on the shelf] 1 , Petra put the book t 1
This PP does not move to the subject position, which is already occupied by Petra.
The position it moves to is to the left of the subject and it is not really a position that
we easily claim to be integral to all sentences given that in many it is not filled at all.
Furthermore, this position has a number of things in common with an adjunct, in
that an unlimited number of elements can undergo preposing:
(101) a Petra put the book [on the shelf] [without telling me] [yesterday]
b [yesterday] 1 , [without telling me] 2 , [on the shelf] 3 , Petra put the book t 3 t 2 t 1
If we were to propose that these movements put the moved elements into empty
positions, we would have to suppose the existence of an indefinite number of empty
positions at the front of the clause which sit there waiting for something to move into
them. This does not seem a reasonable assumption.
Moreover, there are instances that we might want to analyse as a case of movement
where an element moves to a position that is blatantly not empty. For example:
(102) a we will not be moved
b we won’t be moved
In (102b) it might be claimed that the negative element moves to the position
occupied by the modal auxiliary and the two somehow join together to become a
single word. Again there is something like an adjunction formed in this case with a
word being created from two independent words, like a compound noun (in this case
the ‘compound’ is a verb).
Because of examples such as these it has been proposed that there are two types of
movement. One, known as substitution, moves an element into a vacant position. The
other, called adjunction, creates an adjunction structure by the movement. Thus, PP
preposing might be argued to move the PP to a position adjoined to the left of the
clause: