1. What is modality?
Modality is concerned with expressing opinions and attitudes. Modality in general is defined similarly in many reference books. For example
Quirk, Greenbaum, Leech and Svartvik (1985) claim, that “at its most general, modality may be defined as the manner in which the meaning of a clause is qualified so as to reflect the speaker’s judgment of the likelihood of the proposition it expresses being true” (p. 219). However, the authors deal with the term modality mainly in connection with the category of modal auxiliary verbs and the topic is not considered in wider view.
Similarly Huddleston (1984) introduces modality briefly as a broad term for the kind of meaning characteristically expressed by the modals. On the other hand he gives a good distinction between mood as a category of grammar and modality as a category of meaning. He says: “The distinction is analogous to that between tense and time and it would be useful if we had similar pair of terms for talking about aspect” (pp. 165 - 166).
Mood refers to a grammatical category of the verb which has a modal function and is expressed inflectionally (distinct sets of verbal paradigms). Modality is a semantic category belonging to elements of meaning that language expresses (Bybee, & Fleischman, 1995).
Neither Palmer (2001) gives a general definition but also associates modality with categories of tense and aspect, because all three are “concerned with the event or situation that is reported by the utterance (…). Tense is concerned with the time of the event, while aspect is concerned with the nature of the event. Modality is concerned with the status of the proposition that describes the event” (p. 1).
2. Types of modality
Most linguists accept the existence of at least three types of modality: epistemic, deontic and dynamic [Huddlston 2002: 6.5.(d)] English grammars often refer to epistemic and deontic modality as belief and action modality, respectively.