Imperfective

When learning Russian, it's important to understand the difference between perfective and imperfective verbs.

Many textbooks on Japanese claim that the language has verbal tenses, namely, the past and the non-past, but many academics proclaim that Japanese has really verbal aspects, not tenses, namely the perfective and imperfective aspects. In this way, Tagalog is more like Japanese, with its complete, progressive, and contemplative as main aspects.

The Slavic influence on Yiddish isn't just vocabulary and suffixes, but also extends to the verb system, where many verbs have perfective and imperfective forms.

That's why there are perfective and imperfective aspects in Russian. Try to familiarize yourself with them!

In the last chapter, we observed the rise of an imperfective marker in English, the Progressive, as the dominant and surviving member of a wider paradigm of imperfective aspectual functions in Old English, but which were no longer marked in the same way in later stages of the history of English.

The former is the basic imperfective subjunctive, while the latter is prominent or intensified.[…]While the present subjunctive is imperfective in aspect, the perfect subjunctive is imperfective in aspect and spatially proximate.

Consider, then, the result of applying these tense morphemes to a perfective or an imperfective verb.

Examples of past imperfectives are shown in (42).

These putative indeterminate imperfectives are innovative in form precisely because they add a manner meaning to the range of lexical meanings available to Proto-Slavic motion verbs.

Past imperfectives are also unproblematic because imperfectives are mass-like in nature, hence contractible.