Spatial Grammar

Spatial grammar is the set of grammatical rules that signed languages express through the three-dimensional signing space in front of the signer, rather than through linear word order. Signers establish referents at specific spatial loci, use directional verbs that agree with those loci, employ classifier predicates to represent objects and their relative positions, and shift body orientation and eye gaze to mark role shifts in reported speech. Because these structures operate simultaneously across body, face, and hands rather than sequentially, spatial grammar is difficult to capture with text-based representations and is a persistent weak point in AI sign-language generation, where referential drift and inconsistent pointing gestures degrade comprehension.