Constraining non-local dependencies in tree -adjoining grammar: Computational and linguistic perspectives
Constraints on structural locality have been the focus of much work in syntax—although a lexical item may be dislocated from its canonical position without bound, there are restrictions prohibiting such dislocation in various cases. The constructions loosely grouped under the term “reduced constructions” in Romance and Germanic languages, such as clitic climbing and long scrambling, are an important test case for the characterization of locality constraints, due to their somewhat unusual properties. We examine reduced constructions from the perspective of Tree Adjoining Grammar (TAG), a formalism for composing bounded phrase structure representations. TAG is an attractive candidate for the representation of natural language syntax for both its linguistic and computational properties. It forces the substantive theory of syntax to be stated over small structural domains, the “elementary trees”, and various syntactic locality constraints fall out from the restricted nature of a TAG derivation. As a consequence of TAG's unique properties, an analysis of the reduced constructions commonly used in other frameworks cannot be implemented in TAG. We show that the problem raised for TAG by the reduced constructions can be seen as one case of an underlying structural problem also existing for the core cases of unbounded dependencies. This leads to a revision of TAG that retains TAG's notion of locality, with the consequent desirable computational properties, and the further consequence that locality constraints on reduced constructions fall out from the TAG machinery. We also demonstrate that cross-linguistic differences in two cases of reduced constructions, Spanish clitic climbing and German long scrambling, can be reduced to differences in the specification of the elementary trees. Interesting questions are raised about the competence/performance distinction. Locality is retained in this system by sacrificing coverage of some theoretically possible cases of long scrambling that never actually occur, due to their excessive complexity. While such cases are usually ruled out by performance considerations, this work shows that such cases can instead fall outside the competence grammar itself.
Kulick, Seth Norman, "Constraining non-local dependencies in tree -adjoining grammar: Computational and linguistic perspectives" (2000). Dissertations available from ProQuest. AAI9976441.