Verb aspect formation

  1. It's almost impossible in Russian to predict how a perfective verb is formed. Most dictionaries will list both forms in the same entry. Some perfectives are formed by adding a prefix to the imperfective form:
    imperfectiveperfective
    делатьсделать
    строитьпостроить

  2. Some aspect pairs are formed by extending the stem of the imperfective form with an infix:

    imperfectiveperfective
    показыватьпоказать
  3. If one verb of the pair is conjugation I, and the other is conjugation II, most often the conjugation II verb will be perfective:
    imperfectiveperfective
    кончатькончить
    отвечатьответить
  4. Some aspect pairs are formed from two different stems:
    imperfectiveperfective
    говоритьсказать