Most Russian verbs come in pairs: an imperfective verb for an action as a process, a habit or a general fact (читать, chitat', to read), and a perfective verb for one complete action with a result (прочитать, prochitat', to read through). Before you choose, ask: am I talking about the activity itself, or about getting it done once?
English has a dozen ways to place an action in time: I read, I was reading, I have read, I had been reading. Russian has only three tenses, past, present and future, and covers the rest with aspect. Instead of changing the auxiliary, Russian changes the verb. That is why a Russian dictionary gives you two verbs for "to write" and English speakers feel they have to learn every verb twice. They do, and it is worth it.
| English | Imperfective (process, habit) | Perfective (done once, result) |
|---|---|---|
| to do, make | делать (delat') | сделать (sdelat') |
| to write | писать (pisat') | написать (napisat') |
| to read | читать (chitat') | прочитать (prochitat') |
| to drink | пить (pit') | выпить (vypit') |
| to buy | покупать (pokupat') | купить (kupit') |
| to open | открывать (otkryvat') | открыть (otkryt') |
| to call (phone) | звонить (zvonit') | позвонить (pozvonit') |
| to say, tell | говорить (govorit') | сказать (skazat') |
| to take | брать (brat') | взять (vzyat') |
Pairs are built three ways: a prefix (на-, про-, с-, вы-, по-), a change of suffix (покупать and купить), or a completely different word (говорить and сказать). A prefix is a hint, not a rule: покупать starts with по- and is still imperfective.
One small word shows the difference clearly. Я читал книгу два дня means "I spent two days reading the book", with no claim that you finished. Я прочитал книгу за два дня means "I read the book in two days", and you did finish it. A plain length of time goes with the imperfective; за plus a length of time goes with the perfective.
This is the single most common aspect mistake English speakers make. When you conjugate a perfective verb in what looks like the present tense, it means the future. Я напишу письмо is "I will write the letter", not "I write the letter". The imperfective future uses буду (budu) plus the infinitive, and буду never goes with a perfective verb.
| English | Russian | Aspect |
|---|---|---|
| I'm writing a letter (right now). | Я пишу письмо. | Imperfective present |
| I was writing a letter when you called. | Я писал письмо, когда ты позвонил. | Both: background, then the event |
| I wrote the letter (it's done). | Я написал письмо. | Perfective past |
| I'll be writing all evening. | Я буду писать весь вечер. | Imperfective future |
| I'll write the letter tomorrow. | Я напишу письмо завтра. | Perfective future |
| What learners say | Correct | Why |
|---|---|---|
| Вчера я прочитал весь вечер. | Вчера я читал весь вечер. | Duration means process. |
| Каждый день я выпью кофе. | Каждый день я пью кофе. | Выпью is a one-time future: "I'll drink it up". |
| Я буду купить хлеб. | Я куплю хлеб. | Буду never takes a perfective infinitive. |
| Я покупал хлеб, вот он. | Я купил хлеб, вот он. | You are pointing at the result. |
| Я начал прочитать. | Я начал читать. | Start, continue and finish take the imperfective. |
Commands follow the same logic, with a social layer on top. A specific one-time request is usually perfective: Скажите, пожалуйста, где метро? (Could you tell me where the metro is?) or Дайте, пожалуйста, меню (The menu, please). Invitations to do something the other person is about to do anyway are often imperfective and sound warm: Проходите! (Come in!) Садитесь! (Have a seat!)
Negative commands are usually imperfective: Не открывай окно (Don't open the window). A negative perfective works as a warning about something that might happen by accident: Не забудь ключи (Don't forget your keys).
The fastest way to make aspect automatic is to learn every new verb as a pair and to say short, true sentences about your day with both: what you were doing, and what you got done. Telling a tutor what you did yesterday, out loud, forces exactly that choice dozens of times in a few minutes.
Most do. A few verbs have only one aspect, and some, such as использовать (to use) and жениться (to get married, said of a man), can work as either, with context deciding.
Check the dictionary, which marks the imperfective as нсв and the perfective as св. Prefixes often signal the perfective, but not always: покупать has the prefix по- and is imperfective.
Only partly. An English past continuous such as I was reading is imperfective in Russian, but the imperfective also covers habits and general experience, as in Ты читал эту книгу? for Have you read this book?
The imperfective, because you are asking whether the experience exists at all. Ты был в Москве? means Have you ever been to Moscow?
