Aspect with Infinitives in Russian

In Brief

A Russian infinitive still expresses aspect: use the imperfective for an activity, process, repetition, or general situation, and the perfective for one bounded action or intended result. Certain contexts sharpen that contrast: phase verbs normally require the imperfective (начал читать), while modal and evaluative expressions allow both aspects with different meanings (можно входить “entry is allowed” versus можно войти? “may I come in?”).

Overview

An infinitive is the dictionary form of a verb—the form translated by English “to read,” “to enter,” or “to close.” In Russian, infinitives such as читать, войти, and закрыть also carry aspect, the speaker’s way of presenting an action. The imperfective presents an activity from the inside, without making its endpoint central; the perfective presents one bounded event, usually with a result or natural endpoint.

English does not mark this distinction consistently. “I forgot to close the door,” “you may enter,” and “it is difficult to explain” all contain ordinary English infinitives. Russian must choose between forms such as закрывать/закрыть, входить/войти, and объяснять/объяснить. The choice is not determined by the English word “to.” It depends on what the Russian sentence means.

At B2, the basic aspect rules learned earlier remain valid, but you apply them inside larger constructions: after phase verbs, modal verbs and impersonal words, adjectives, and verbs such as забыть “forget” or успеть “manage in time.” Negation strongly favors the imperfective in several common patterns, but it does not mechanically ban the perfective.

How It Works

Begin with the intended view of the action

Before looking at the word that introduces the infinitive, ask whether the sentence presents an activity or one result.

Meaning	Imperfective infinitive	Perfective infinitive
activity or process	читать “to be reading”	—
repeated or habitual action	закрывать “to close regularly”	—
action in general	обсуждать “to discuss”	—
one bounded event	—	прочитать “to read through”
intended result	—	закрыть “to get closed”
one successful occurrence	—	обсудить “to discuss and deal with”

The infinitive itself does not show tense or person, but it is not aspect-neutral. In хочу читать, the desire concerns reading as an activity. In хочу прочитать эту статью, it concerns completing one article.

Phase verbs: normally use the imperfective

A phase verb describes a stage of another action—its beginning, continuation, or end. Common examples are начать/начинать “begin,” продолжить/продолжать “continue,” перестать/переставать “stop,” and закончить/заканчивать “finish.” The following action is viewed as an unfolding activity, so its infinitive is normally imperfective.

Phase	Pattern	Example
beginning	начать + imperfective	начать читать “start reading”
continuation	продолжать + imperfective	продолжать работать “continue working”
stopping	перестать + imperfective	перестать спорить “stop arguing”
finishing an activity	закончить + imperfective	закончить писать отчёт “finish writing the report”

Notice that the phase verb and the infinitive have separate aspect choices. Начал is perfective because the beginning occurred as an event, but читать is imperfective because it names the activity that began: Он начал читать книгу. A form such as начал прочитать is normally impossible in this meaning.

Do not confuse закончить писать with написать. The first explicitly marks the end of the writing activity; the second presents the completed result directly. Both can be natural, but their structures and focus differ.

Modal verbs and impersonal words: either aspect may occur

A modal expression describes possibility, permission, necessity, desire, or ability rather than the action itself. Russian examples include мочь “can,” хотеть “want,” нужно/надо “it is necessary,” можно “one may/can,” and нельзя “one must not/cannot.” These expressions usually do not dictate one aspect. The intended meaning does.

Intended meaning	Natural choice	Example
general ability or activity	imperfective	Я могу долго работать. “I can work for a long time.”
ability to obtain one result	perfective	Я могу закончить сегодня. “I can finish today.”
general permission	imperfective	Здесь можно парковаться. “Parking is allowed here.”
permission for one act	perfective	Можно открыть окно? “May I open the window?”
ongoing or repeated obligation	imperfective	Нужно больше читать. “You need to read more.”
one task to complete	perfective	Нужно отправить письмо. “The letter needs to be sent.”

With хотеть, compare Я хочу учить русский “I want to study Russian” with Я хочу выучить эти слова “I want to learn these words fully.” The first names an activity; the second sets a result.

Evaluative words and adjectives

Russian often evaluates an action with an impersonal word or a short neuter adjective: легко “easy,” трудно “difficult,” важно “important,” полезно “beneficial,” приятно “pleasant,” or опасно “dangerous.” Again, general activity favors the imperfective, while a particular problem or outcome favors the perfective.

• Полезно гулять каждый день. — Walking every day is beneficial.
• Эту задачу трудно решить. — This problem is difficult to solve.
• С ним приятно разговаривать. — He is pleasant to talk with.
• Важно проверить все цифры. — It is important to check all the figures.

The noun phrase often helps. Решать такие задачи трудно discusses solving that kind of problem in general. Эту задачу трудно решить singles out one problem and its successful solution.

Negation often shifts the choice toward the imperfective

A negated infinitive often means that an activity is unnecessary, unwanted, or forbidden in general. The imperfective is therefore common after не нужно, не надо, не стоит, and prohibitive нельзя.

• Не нужно волноваться. — There is no need to worry.
• Не надо ничего покупать. — You do not need to buy anything.
• Здесь нельзя курить. — Smoking is prohibited here.
• Не стоит спорить из-за мелочей. — It is not worth arguing over small things.

This is a meaning tendency, not a rule that “negative equals imperfective.” A perfective infinitive remains natural when the negative expression concerns one concrete result:

• Он боялся не успеть на поезд. — He was afraid he would not make the train.
• Можно не отвечать на последний вопрос. — You may leave the last question unanswered.
• Главное — не забыть закрыть окно. — The main thing is not to forget to close the window.

A particularly useful contrast is нельзя + infinitive. With the imperfective it commonly expresses prohibition: Нельзя входить “Do not enter / entry is forbidden.” With a perfective infinitive it can express impossibility: Эту дверь нельзя открыть без ключа “This door cannot be opened without a key.” Context, not aspect alone, gives the final interpretation.

Verbs of remembering, forgetting, trying, and managing

Some controlling verbs make the distinction especially visible.

With забыть “forget,” the perfective commonly names a specific intended action that did not happen: Я забыл закрыть дверь. The imperfective can describe a recurring action or a skill/procedure, but it usually needs supporting context: Он постоянно забывает выключать свет “He constantly forgets to turn off the light.”

With успеть “manage in time,” the perfective infinitive emphasizes completing one task: успеть закончить “manage to finish.” An imperfective infinitive can focus on fitting in some amount of activity: В поезде я успел немного почитать “I managed to do a little reading on the train.”

With пытаться/попытаться “try, attempt,” either aspect is possible. Пытался открыть дверь often portrays the attempt as an ongoing effort; попытался открыть дверь presents one attempt. The infinitive открыть is perfective because opening the door is the sought result—even if the context later says the attempt failed.

Examples in Context

Russian	English	Note
Он начал читать книгу.	He started reading a book.	A phase verb takes an imperfective activity.
После перерыва мы продолжили обсуждать проект.	After the break, we continued discussing the project.	The discussion is already in progress.
Она перестала пить кофе вечером.	She stopped drinking coffee in the evening.	Stopping a repeated activity.
Можно войти?	May I come in?	Permission for one bounded action.
Здесь можно фотографировать.	Photography is allowed here.	General permission.
Мне нужно чаще звонить родителям.	I need to call my parents more often.	Repeated obligation.
Мне нужно позвонить врачу сегодня.	I need to call the doctor today.	One concrete task.
Я забыл закрыть дверь.	I forgot to close the door.	A specific intended result was not achieved.
Он часто забывает закрывать дверь.	He often forgets to close the door.	A recurring failure.
Не нужно волноваться.	There is no need to worry.	General negated necessity.
Эту ошибку легко исправить.	This mistake is easy to correct.	One identifiable result.
На ошибках полезно учиться.	It is useful to learn from mistakes.	General activity.
Боюсь не успеть закончить отчёт.	I am afraid I will not manage to finish the report.	Negation does not remove the result focus.
Эту дверь нельзя открыть без ключа.	This door cannot be opened without a key.	Perfective under нельзя expresses practical impossibility.
В музее нельзя трогать экспонаты.	You must not touch the exhibits in the museum.	Imperfective under нельзя gives a general prohibition.

Common Mistakes

Using the perfective after a phase verb

• Wrong: Он начал прочитать книгу.
• Right: Он начал читать книгу.
• Why: Начать marks the beginning of an activity, so the following infinitive is imperfective. If completion matters, say Он прочитал книгу or add later context.

Treating English “can” as one fixed Russian pattern

• Wrong: Здесь можно войти when you mean that entry is generally allowed.
• Right: Здесь можно входить.
• Why: General permission normally uses the imperfective. Можно войти? is excellent Russian, but it asks permission for one act of entering.

Automatically choosing the perfective for every task

• Wrong: Мне нужно прочитать больше when the intended meaning is “I need to read more regularly.”
• Right: Мне нужно больше читать.
• Why: The imperfective names reading as an ongoing habit. Use прочитать with a bounded object or amount: прочитать эту главу.

Assuming every negative infinitive must be imperfective

• Wrong: Боюсь не успевать на поезд for one particular train.
• Right: Боюсь не успеть на поезд.
• Why: The feared failure concerns one concrete outcome. Negation often favors the imperfective, but a specific result still calls for the perfective.

Confusing prohibition with impossibility after нельзя

• Potentially misleading: Эту дверь нельзя открывать.
• Better for “cannot be opened”: Эту дверь нельзя открыть.
• Why: Нельзя открывать normally sounds like “one must not open it,” while нельзя открыть can mean that achieving the result is impossible. Context may blur the boundary, so make the intended meaning explicit when needed.

Usage Notes

Russian speakers often rely on context rather than stating “generally” or “once.” A plural object, a frequency adverb, or a time phrase can make the aspect choice clear: часто писать письма is repeated, while написать письмо сегодня is one task. Learn the infinitive together with these clues rather than as an isolated pair.

Aspect pairs are not always perfect synonyms except for aspect. Prefixes can add lexical meaning, and some verbs have several possible partners. Check a good dictionary before assuming that adding a prefix merely creates the perfective. For example, читать can lead to прочитать “read through,” дочитать “finish reading what remains,” or перечитать “reread,” each with a different result.

In instructions and public notices, imperfective infinitives often describe standing rules: Не входить, Не курить, Руками не трогать. These are concise prohibitions, not incomplete sentences. A perfective infinitive in a warning may instead focus on preventing one outcome: Не забыть выключить свет is naturally read as a reminder, “Don’t forget to turn off the light.”

Beyond the Basics / Advanced Use

Aspect can also reveal the speaker’s assumptions about control and success. In Он пытался открыть окно, the perfective открыть names the intended result; it does not claim that the window opened. The controlling verb пытался places that result inside an attempt. Similarly, забыл закрыть implies that closing was intended but did not occur. Perfective aspect presents a target endpoint, not necessarily a real completed event when it is embedded under words such as “try,” “forget,” “want,” or negation.

Some modal contrasts are pragmatic rather than purely factual. Вы можете подписать здесь? asks whether the listener can perform one requested act and often functions as a polite request. Вы можете подписывать документы? asks about general authority or ability to sign documents. English may use “can sign” in both cases; Russian aspect distinguishes the communicative purpose.

The imperfective may also be used to “name the action” without committing to its occurrence. Questions such as Стоит ли покупать эту машину? ask whether buying such a car is advisable as an activity or decision under consideration. Стоит ли купить эту машину? places more weight on one prospective purchase. Both can be grammatical; the speaker chooses the frame.

Finally, aspect interacts with the aspect of the controlling verb. Compare я пытался открыть “I was trying / tried repeatedly to open” and я попытался открыть “I made one attempt to open.” Here пытался/попытался controls the shape of the attempt, while открыть keeps the opening as its desired endpoint. Reading Russian accurately often means tracking both verbs separately.

Practice Tips

1. Build pairs around one context, not isolated infinitives: можно входить / можно войти, нужно читать / нужно прочитать главу, трудно решать / трудно решить. Say aloud what changes: general activity versus one result.
2. When choosing an infinitive, ask three questions: “Is this repeated or general?”, “Is there one concrete object or deadline?”, and “Does the first word describe a phase?” These questions solve most everyday cases.
3. Collect real examples of можно, нельзя, нужно, забыть, and успеть from reading or listening. Underline the infinitive and label the meaning “activity,” “rule,” “single act,” or “result.”

Related Concepts

• Prerequisite: Aspect Usage Rules — reviews the basic process, repetition, completion, and result contrast used throughout this topic.
• Next steps: Aspect: Advanced Usage — develops subtler choices involving cancelled results, imperatives, limited duration, and discourse effects.