Aspektid

Aspektid, in linguistic terms, refer to the grammatical category that expresses how an action or event unfolds over time. Unlike tense, which locates an event in time, aspect describes the internal temporal structure—ongoing, completed, habitual, or repeated.

Most languages distinguish at least two aspectual classes: imperfective and perfective. The imperfective aspect covers ongoing actions, habitual or repeated actions, and actions without focusing on their boundaries. The perfective aspect treats events as complete wholes, with emphasis on their boundaries or results. Some languages add progressive, habitual, or perfect-oriented shades, and the exact set of marks varies by language.

Aspect interacts with tense and mood but is, in principle, independent. It is often marked by verbal prefixes or suffixes, auxiliary verbs, or separate words.

Examples: English expresses imperfective aspect in "I am eating" and "I eat (often)"; perfective in "I ate" or "I have eaten" depending on analysis. Estonian likewise marks aspect in a verbal form, with both imperfective and perfective forms used to express timing and completion nuances.