Chapter 3 - Basic Concepts of Syntactic TheoryThe structure we end up with is one that is perfectly compatible with X-bar
principles. In other words, the movement seems not to have radically altered the
structure. Suppose we assume a restriction on all movements, that they cannot alter
structures in a way that would violate basic X-bar principles:
(58) Structure Preservation Principle
no movement can alter the basic X-bar nature of structure
This would rule out immediately a very large class of movements possible under the
assumption of (56).
The important point to recognise is that the assumption of (56) and the imposition
of a restriction such as (58) offer a far simpler and general theory of what can move
where than would a theory that was made up of lots of specific rules telling us what
can move where and under what conditions in particular cases. Of course, (56) and
(58) together still do not constitute a particularly accurate theory of movement and
there are still many movements allowed under these assumptions that do not actually
occur. However, even if we add five or ten more restrictions of the kind in (58) we
would still have a more general theory of movement than the literally hundreds of
movement rules that would be required to describe specific cases of movements. We
will see that the number of restrictions required to capture the majority of facts about
movement is surprisingly small.
2.2 D-structure and S-structure
An immediate consequence of accepting movements as a part of grammatical
description is that there are at least two levels that we can describe the structure of any
sentence: a level before movement takes place and a level after movement has taken
place.
(59) structure
movement
structure
The difference between the two levels of structural description will simply be the
positions that the moved elements occupy, given the above assumption that
movements do not actually alter the structure. For example, consider the following two
sentences:
(60) a Mary met Mark in the park
b in the park, Mary met Mark
In (60a) the PP in the park is an adjunct to the VP, modifying the VP by adding
information about where the meeting took place. In (60b) the PP has moved to the
front of the sentence, in a similar way to that in which topics are moved to the front.
We can call this movement preposing. Before the preposing takes place, the PP is in
its VP adjoined position: