This dissertation investigates the semantics, pragmatics, and syntax of propositional attitude reports; in particular, how assertion and presupposition are reflected in these different parts of the grammar. At the core of the dissertation are factive attitude reports, involving predicates like know, discover, realize, resent, appreciate, and like. Since Stalnaker (1974), factivity is taken to encompass both the discourse status of the embedded proposition p as Common Ground and the projection of the inference that the speaker is committed to p from the scope of operators—in both cases, unlike asserted content. Syntactically, factivity and assertion are argued to provide the semantic-pragmatic underpinnings for a range of complementation pat...