occurrence

An actual instance when a situation occurs; an event or happening.

Since the mid-1980s, when Indonesia first began to clear its bountiful forests on an industrial scale in favour of lucrative palm-oil plantations, “haze” has become an almost annual occurrence in South-East Asia. The cheapest way to clear logged woodland is to burn it, producing an acrid cloud of foul white smoke that, carried by the wind, can cover hundreds, or even thousands, of square miles.

The lexical aspect (aktionsart) of verbs or predicates that change in or over time.

The time interval of an occurrence—a temporal instantiation—is a single occasion. However, a series of such occasions can fall within a certain time interval; in this case we may represent the occurrence as a single situation (cf. I ran off and on for an hour, I ran and ran for an hour, I would run and then run some more).

The most basic Aktionsart distinction is between states and occurrences. […]Based on consideration of inherent differences between the events involved, Vendler distinguished three different types of occurrence, achievements, activities, and accomplishments.