Deducing the future and distinguishing the past: Temporal interpretation in modal sentences in English

This dissertation concerns the semantic analysis of modals in English with the aim of accounting for variation in their temporal interpretation under different modal readings. A paradigm of modals is considered that undergo an alternation between epistemic, non-future readings and non-epistemic, future readings. Each distinct temporal interpretation is seen as due to interactions between a modal base and general interpretive principles. A disparity principle requires the content of the modal to hold only in some and not all worlds selected by the modal base. If the modal base is only associated with branching futures, the disparity principle results in future, or partially future readings. If the modal base is epistemic, the disparity principle by itself allows past, present, or future readings, but the supplemental requirement to make first distinctions first guarantees non-future readings. One of the key modals in the paradigm is will and arguments are given that this is truly a modal, and that its temporal interpretation is not due to tense marking. These arguments include temporal interpretations involving future readings with present overlap as well as a defense on conceptual grounds of treating the future as open and will as a universal quantifier over the implicit possibilities. One result is an account of the semantic difference between will and its past tense form would in terms of using the most up-to-date ordering source available. The general motivation for disparity is ordering, and differences between modals with similar temporality are seen as due to differences in the ordering source. Entailment relations between future will, deontic must, and potential can are thereby captured. The relation between imperatives and deontic modals is examined in terms of the general approach offered here, and preliminary ideas are discussed for applying the treatment to the temporal interpretation of conditionals.