The imperfective aspect is a grammatical term used in language to indicate ongoing or continuous actions. Synonyms for this term include the present continuous, progressive aspect, continuous tense, or simply, the imperfect tense. These different terms may be used interchangeably depending on the language, context, or structure of the sentence. In some languages like Russian, the imperfective aspect is contrasted with the perfective aspect, which indicates completed or finished actions. Other languages like English do not have this grammatical distinction, but still make use of the imperfective aspect to express the duration of an action in progress.