The grammar of knowledge

The empirical goal of this paper is to establish a generalization about the expression of knowledge. Unmarked declaratives are used in context of certainty: uncertainty has to be marked, but certainty need not be and if it is different strategies have different interpretive effects. The analytical goal is to argue for a grammatical analysis of this generalization. It is argued that the interpretation of certainty comes about (covertly) marking declaratives as being part of the speaker's epistemic state. This grammatical analysis is compared to an alternative according to which the interpretation of certainty is a pragmatic effect, based on Gricean reasoning. Empirical evidence is provided that favors the grammatical analysis. The generalization about the expression of certainty as well as its grammatical analysis has far-reaching consequences for cross-linguistic comparison, for philosophical theories of assertion, as well as for human AI interaction.