A Formal Foundation for a and A-bar Movement

It is natural to think of sentences in natural language as exhibiting longdistance dependencies. A surprising fact, established over decades of linguistic investigation, is that such dependencies are naturally treated as falling into one of two groups. ‘A’ dependencies (typified by raising, passivization, etc) are those which allow for re-binding, which disallow reconstruction, and which do not license parasitic gaps. ‘A-bar’ dependencies (typified by whmovement, relativization, etc) disallow re-binding, allow reconstruction, and do license parasitic gaps. Furthermore, when an expression enters in to both A and A-bar dependencies, all of its A dependencies must ‘precede’ its A-bar dependencies [2]. This relational property of dependencies is known as the ban on improper movement. In the government and binding (GB) tradition, all of these properties of these two dependency types must be independently stipulated—none follow from any of the others. Here I will present a simple and constrained formal system in the GB tradition with two kinds of long distance dependency forming operations, the interaction of which gives rise to the major syntactic property of A and A-bar movement: the ban on improper movement. Additionally, the resulting system seems to provide the right kinds of structures over which to naturally enforce the other characteristic semantic properties (reconstruction and re-binding) of each kind of movement. The difference between A and A-bar dependencies as regards the licensing of parasitic gaps cannot be made to follow from the formal architecture of the system, as neither do parasitic gaps. However, natural grammars can be written for fragments of English in which the difference in licensing of parasitic gaps obtains without stipulation.