Abstract

It has long been recognized that natural language expressions for space and time share basic similarities. Despite these similarities, studies in natural language semantics have focused almost exclusively on the semantics of time. It is argued here that the fundamental similarities between the domains of space and time, and the rich body of work in the semantics of temporal expressions, jointly motivate an excursion into the semantics of space. Drawing on a logical tradition originating with Russell and Whitehead, which has articulated formal similarities between the two domains, a semantics for spatial locatives is defined using a version of Discourse Representation Theory jointly developed by Hans Kamp and Christian Rohrer. The semantic theory proposed here is formalized using an ontology in which events are primitive, and spatial points and regions are constructed as secondary and tertiary objects. Kamp and others have described such constructions for the temporal domain. A spatial construction is presented here, and a notion of spatial orientation consistent with this construction is formalized in the context of DRT. The resulting semantic theory is applied to expressions using simple locative prepositions such as at, on, in; projective prepositions such as behind, to the left; path expressions such as toward the mountains, along the river; and to topics including spatial anaphora and iterated locatives.