Almost every Russian verb comes as a pair: one imperfective and one perfective. There is no separate set of tenses for "continuous" or "completed" the way English has — that work is done by aspect. Choosing the right one is the key to sounding natural.
1. Imperfective vs perfective
- Imperfective views the action as a process, a repetition, or simply the bare fact that it happened — with no focus on a result.
- Я писал письмо. — I was writing a letter. (process)
- Я читаю каждый день. — I read every day. (repetition)
- Ты смотрел этот фильм? — Have you seen this film? (just the fact)
- Perfective views the action as a single, complete whole with a result or a clear end-point.
- Я написал письмо. — I wrote (and finished) the letter.
- Я прочитал книгу. — I read the book (all the way through).
The same event, two viewpoints: писать keeps you inside the process; написать stands at the finish line.
2. How the pairs form
Partners in a pair are related in one of three ways.
2.1 Suffix / stem change
The main, productive pattern, usually building the imperfective from the perfective: решить → решать, дать → давать, открыть → открывать.
2.2 Prefix
A prefix can make a perfective: писать → написать, делать → сделать, строить → построить.
2.3 Suppletive
A few pairs use different roots: говорить → сказать, брать → взять, класть → положить, ловить → поймать.
Not every prefix makes a pure pair
A prefix only gives a true aspect partner when it adds nothing but completion (писать → написать). When the prefix adds meaning, you get a new verb, not a pair: переписать (to rewrite), подписать (to sign), выписать (to write out). Each of those then forms its own imperfective by suffix: переписать → переписывать.
3. Aspect across the tenses
Aspect interacts with time in a way that surprises beginners.
3.1 Present
Only the imperfective has one. A perfective form with present endings means the future (see below). This is exactly why the present tense is built only on imperfective verbs — the perfective's "present-shaped" form has already been claimed by the future.
3.2 Past
Both aspects exist: писа́л (was writing / used to write) vs написа́л (wrote, finished). The full past-tense machinery — gender and number agreement, not person — lives in the past tensesoon guide.
3.3 Future
There are two different shapes:
| Aspect | Future | Meaning |
|---|---|---|
| imperfective | буду + infinitive | буду писать — I will be writing / will write (process) |
| perfective | conjugated like the present | напишу — I will write (and finish) |
The compound imperfective and the perfective each have their own logic, laid out fully in the future tensesoon guide.
буду never meets a perfective
The compound future uses буду / будешь … with an imperfective infinitive only. буду написать is impossible — the perfective already carries its own future in напишу, прочитаю, сделаю.
4. The "annulled result" nuance
In the past, the imperfective can quietly signal that a result was reversed:
- Он открывал окно. — He opened the window (and it may be closed again now / "did someone open it?").
- Он открыл окно. — He opened the window (and it is still open).
- Ко мне приходил врач. — A doctor came (and has left).
- Ко мне пришёл врач. — A doctor has come (focus on the arrival / he may still be here).
This "there and back" reading is especially common with the verbs of motionsoon, where aspect and direction work together.
5. Aspect in commands
The imperativesoon chooses aspect by intention.
5.1 Affirmative commands
Perfective for a single, concrete request — Открой окно! (Open the window!); imperfective for an invitation, permission, or a process — Открывай!, Садитесь, пожалуйста!
5.2 Negative commands — the split that matters
- A prohibition uses the imperfective: Не закрывай дверь! (Don't shut the door!), Не бери это! (Don't take that!).
- A warning about an accidental, unwanted event uses the perfective, often with смотри: Не упади! (Don't fall!), Смотри не опоздай! (Mind you're not late!).
6. Verbs that take only one aspect after them
Phase verbs — those that start, continue, or stop an action — take only an imperfective infinitive. This is a hard rule, not a tendency:
- начать / начинать, продолжать / продолжить, кончить / кончать, перестать, прекратить.
- Я начал читать. — I started reading. (never «начал прочитать»)
- Он перестал курить. — He stopped smoking.
The same goes for verbs of habit and learning: научиться, привыкнуть, устать + an imperfective infinitive (научился плавать).
7. Biaspectual verbs
A small class works as both aspects with one form; only context (and the future) tells them apart: велеть, казнить, обещать, ранить, женить, and most loans in -овать / -ировать — организовать, использовать, информировать, атаковать.
- Завтра я организую встречу. — Tomorrow I'll organise a meeting. (perfective sense)
- Я обычно организую встречи. — I usually organise meetings. (imperfective sense)
8. Try it
Drill the present-tense forms of the imperfective писать — and notice the personal pronouns that the verb acts on as subjects:
писать — to write (imperfective)
Common mistakes
- Using the perfective for a repeated or habitual action: каждый день я пишу (imperfective), not напишу.
- Saying буду написать — the compound future takes only the imperfective.
- Putting a perfective infinitive after a phase verb: it is начал читать, not начал прочитать.
- Using the perfective in a negative command meant as a prohibition: Не закрывай! (don't shut it), reserving the perfective for warnings (Не упади!).
9. Test yourself
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Connected grammar
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