Using the methodology of conversation analysis, this dissertation examines the grammatical resources that participants deploy to track and display relevant knowledge states as they navigate the social world. Specifically, it investigates the role that epistemics plays in the grammatical formulation of turns at talk, and explicates how the epistemic claims made by a particular grammatical format are deployed to do social actions. Chapter 1 defines relevant concepts and establishes the analytical framework for the study. Chapter 2 establishes the context for the study by providing a comprehensive cross-disciplinary literature review on work done in linguistics, discourse analysis and conversation analysis over the past 50 years as it relates to grammar and epistemics. It is argued that while a large number of studies have implicitly acknowledged the role of epistemics in the grammatical formulation of utterances, few studies outside of the areas of conversation analysis and interactional linguistics have adequately acknowledged the role that epistemics plays in the grammatical formulation of turns at talk. Chapter 3 examines A- and B-event declaratives (akin to Labov and Fanshel's (1977) notion of A- and B-event statements) for their epistemic underpinnings and the interactional consequences of their deployment both sequentially and in terms of the actions they do. Evidence is provided for the observation that the declarative is a preferred format for talk about the self and a dispreferred format for talk about the other. It is further argued that grammatical variations on the declarative (e.g., reverse polarity tags, so-prefacing and A-perspectivizing) are resources for downgrading an epistemic claim made by a turn at talk and that the type of resource deployed indexes a particular epistemic state. Chapter 4 illustrates the application of an epistemic framework to the analysis of interaction in a particular context - that of physician/patient interaction with special attention to the epistemics of declaratively and interrogatively-formatted utterances targeting B events and the actions these utterances do. The chapter's findings include a discussion of how physicians deploy declaratives and interrogatives in different sequential contexts, and further, deploy these two formats to do different actions. Chapter 5 investigates the epistemic distinctions between 1) reverse polarity tag questions (RPTs) and same polarity tag questions (SPTs) and 2) reverse polarity tag questions with rising intonation and reverse polarity tag questions with falling intonation. It is found that in the case of SPTs and RPTs, these two question types differ with respect to the authorship of the information contained within the turn. With respect to RPTs with rising and falling intonation, it is found that the former are used in utterances that are ancillary to the action-in-progress and can be either inclusive or preclusive in nature, whereas the latter are central to and constitutive of the action-in-progress. Chapter 6 provides a summary of each of the substantive chapters and makes suggestions for future research.