modaalit

Modaalit, or modal verbs, are a class of auxiliary verbs used to express modality—the speaker’s stance toward the truth of a proposition. They convey attitudinal nuances such as possibility, necessity, ability, permission, or obligation, rather than concrete actions by themselves.

Semantically, modals cover several broad functions: possibility or likelihood (may, might, can), ability (can, could), permission (may, be allowed to), necessity or obligation (must, have to, should/pitäisi in some languages), and willingness or intention (will, would). The exact inventory and emphasis of these functions vary by language. In Finnish, for example, modulation is expressed with a small set of modaaliverbit such as voida (to be able to), saada (to be allowed to), täytyä (to have to/must), and osata (to know how to), with the main verb typically in the infinitive and the modal itself conjugated for person and number (e.g., minä voin tehdä; sinä täytyy mennä).

Syntactically, modals behave as auxiliary verbs. In English, modals precede the main verb and take only the base form (can go, may be, must be careful). They do not take -s in the third person, form questions by inversion, and negate with not (cannot, should not, might not). In other languages, modals may form part of periphrastic constructions or combine with other verbal forms in more varied ways.

Modality is a broader grammatical category that intersects with mood, tense, aspect, and evidentiality. Modaalit are a central tool in expressing speaker stance, certainty, and social nuance across languages.