Imperfektyw

Imperfektyw, or imperfective aspect, is a grammatical category in many languages, notably in Slavic languages, that marks actions viewed as ongoing, undetermined, or repeated rather than completed. It contrasts with the perfective aspect, which encodes a bounded, completed event.

Imperfective signals duration (the action lasts for some time), habituality (routines), iterativity (repeated actions), or background information in narrative. It does not specify a definite endpoint, focusing instead on the process or repetition of the action.

In Polish, imperfective verbs describe actions not presented as completed at the reference time. Many verbs come in imperfective–perfective pairs, such as pisać "to write" (imperfective) and napisać "to write" (perfective). The present tense of imperfective verbs expresses ongoing actions or general statements. The past tense imperfective (pisałem/pisałaś) describes ongoing or habitual activity in the past; the perfective past (napisałem) marks a single completed action. The future is expressed by either the imperfective periphrasis będę pisać ("I will be writing") or by a simple perfective form like napiszę ("I will write").

Examples: "Piszę list" (I am writing a letter) is imperfective; "Napisałem list" (I wrote a letter) is perfective. "Kiedy byłem młody, chodziłem do szkoły codziennie" expresses habitual past, using imperfective.

Imperfektyw is part of the broader notion of aspect in grammar; in other languages such as Russian, Czech, or Bulgarian, imperfective forms may be achieved by different affixes or periphrastic constructions.