Advances in temporal databases make it increasingly easier to store time-dependent information, creating a need for facilities that will help end-users access this information. In the context of natural language interaction, significant effort has been devoted to interfaces that allow database queries to be formulated in natural language. Most of the existing interfaces, however, do not support adequately the notion of time. Drawing upon tense and aspect theories, temporal logics, and temporal databases, this cross-discipline book examines relevant issues from the three areas, developing a unified theoretical framework that can be used to build natural language interfaces to temporal databases. The framework features an HPSG mapping from English to a formally defined meaning representation language, and a corresponding mapping to a temporal extension of the SL database language. The book is accompanied by a freely available prototype interface, built according to the framework, and implemented using Prolog and ALE. This is the first in-depth exploration of the notion of time in natural language database interfaces. It will be particularly interesting to researchers working on natural language interaction, tense and aspect, HPSG, temporal logics, and temporal databases, especially those who wish to learn about time-related issues in other disciplines.Table of Contents1. Introduction 1 2. Linguistic data and an informal account 19 3. The TOP meaning representation language 71 4. From English to TOP 109 5. From TOP to TSL2 183 6. The prototype NLITDB 239 7. Related work and directions for further research 267 References 283 Index 293 Appendix A: TOP to TSL2 translation rules 299