Verbs of Success and Achievement
When a main verb expresses managing to do something or achieving a successful result, the following verb is almost always in the perfective infinitive.
Because the perfective aspect emphasizes a completed action or a final result, it naturally pairs with verbs of success like суметь (to manage) and удаться (to succeed).
| We managed to complete this assignment on time. | Мы сумели выполнить это поручение вовремя. |
| We managed to achieve this goal, although the schedule was very strict. | Нам удалось достичь этой цели, хотя график был очень жёсткий. |
Attempts and Deadlines
Similarly, verbs that describe making a concrete attempt or having the time to complete a task take the perfective infinitive.
These include попытаться (to try / to make an attempt) and успеть (to manage to do on time), which often appear when discussing tight schedules or strict deadlines.
| I tried to complete the assignment, but failed it. | Я попытался выполнить поручение, но провалил его. |
| Tomorrow is the deadline, and we must manage to submit the report. | Завтра крайний срок, и мы должны успеть сдать отчёт. |
Forgetting and Missing Opportunities
This rule holds even when a desired result is not achieved. Verbs of forgetting, such as забыть (to forget), take the perfective infinitive when referring to a specific action that someone failed to complete.
| He forgot to indicate your achievements in the report. | Он забыл указать твои достижения в отчёте. |
Because perfective verbs emphasize final outcomes, you will also use perfective verbs like провалить (to fail) and упустить (to miss) to describe the finality of missing a critical chance.
| If you fail this project, you will miss your chance. | Если ты провалишь этот проект, ты упустишь свой шанс. |
