modal

A modal is a linguistic term referring to a category of auxiliary verbs that express modality—that is, the speaker's attitude toward the action or state described by the main verb. Common modals in English include can, could, may, might, must, shall, should, will, and would. These verbs are used to convey various nuances such as ability, possibility, permission, obligation, or necessity.

Modal verbs are characterized by their function rather than their grammatical tense individually; however, their meaning can change depending on the context and accompanying tense markers. Unlike full verbs, modals do not inflect for tense in the past or present and are typically followed by the base form of the main verb. For example, in “She can swim,” “can” is a modal indicating ability.

Modals serve several functions in language. They can express likelihood (“It might rain”), ability (“She can dance”), permission (“May I leave early?”), obligation (“You must finish”), or advice (“You should see a doctor”). Some modals also express counterfactual or hypothetical situations, such as “could have” or “might have.”

The use of modals varies across languages, but their primary role remains consistent in expressing speakers' attitudes toward propositions. They are essential in constructing nuanced statements and are widely studied in linguistics and language education to understand modality, tense, and aspect.

In addition to their grammatical role, “modal” can also refer to a range of concepts in different fields, such as in philosophy, where it pertains to notions of possibility and necessity, or in music, where a modal scale refers to a musical framework based on specific patterns of intervals.