Unification-based theories of grammar allow to integrate different levels of linguistic descriptions in the common framework of typed feature structures. Dependencies among the levels are expressed by coreferences. Though highly attractive theoretically, using such codescriptions for analysis creates problems of efficiency. We present an approach to a modular use of codescriptions on the syntactic and semantic level. Grammatical analysis is performed by tightly coupled parsers running in tandem, each using only designated parts of the grammatical description. In the paper we describe the partitioning of grammatical information for the parsers and present results about the performance.