This research investigates the semantics and pragmatics of demonstratives in two languages, English and Arabic, within the framework of relevance theory. The study applies the fundamental distinction between ‘conceptual’ and ‘procedural’ semantics in an attempt to account for the various instantiations of such referring expressions in the two languages. It is argued that demonstratives play a crucial role in aligning the discourse models of the speaker and hearer by encoding procedural semantics instructing the hearer to maintain or create a joint level of attention to the intended referent as opposed to other referential candidates. Within this proposal, it discusses how demonstratives can contribute to both the explicit and the implicit levels of meaning by virtue of the interaction between their encoded semantics and the context in a relevance-driven framework. The study is supported by an analysis of corpus data from both languages in order to supplement theoretical proposals with attested evidence.