Verb aspects are a thing that annoys many learners of Russian, Polish etc. Most learning resources just told me the basics of what they mean, but not how they function in practice.

This is a series where I, as an intermediate Polish learner, attempt to explain some grammatical features common to most Slavic languages in a simple, jargon-free and applicable way. I will be using Polish as my examples but I hope my notes will help learners of other languages too.

The perfective and imperfective verb-pairs took me a long time to figure out, but here’s what they are, in a nutshell:

The perfective aspect of verbs mean one thing: the thing is DONE. FINISHED. ONE ACTION.

The imperfective aspect of verbs can have two meanings:
1. the PROCESS of the action. Starting to do it, but not finishing it yet.
2. doing a thing REPEATEDLY.

Taking Polish as an example: zrobić – to have done; robić – to be in the process of doing OR to do repeatedly, regularly.

Now when to use which is something you need to get a feel for, but I’ll list some general principles I discovered. (I’ll be leaving the formation of the verb forms for another post.)

One conjugation, two past tenses

This is the standard one you get most often in textbooks.

Use the perfective aspect to signify you completed an action:

Wczoraj zrobiłem pracę domową. I did (as in completed, finished) my homework yesterday.

Use the imperfective aspect to say 1) you started or were in the process of doing something, but it doesn’t really matter if you finished it. This often helps introduce another concurrent action.

Wczoraj robiłem pracę domową. I did some homework yesterday. (Probably didn’t finish it.)

Jak wczoraj robiłem pracę domową, widziałem ptaka. While I was doing homework yesterday, I saw a bird.

2) as mentioned above, the imperfective also refers to repeated actions.

Kiedyś codziennie robiłem pracę domową. I used to do homework every day.

Different future tenses with different aspects

Use the perfective aspect in present conjugation to say you intend to complete (as in fully complete) the action:

Jutro zrobię pracę domową. Tomorrow I will finish my homework.

Use the imperfective with future auxiliary (być in Polish: będę, będziesz etc.) to say 1) you will start doing something, but not necessarily finish it.

Jutro będę robił / robić pracę domową. Tomorrow I will be doing homework. (Just some, doesn’t matter how much.)

2) Similarly, it can signify repeated actions.

W następnym tygodniu będę codziennie robił / robić pracę domową. Next week I’ll be doing homework every day.

Asking questions

Here comes the less obvious cases. When you ask a question, you’ll wanna think about whether you need to finish the action or not.

Jak zrobić tę pracę domową? How do I finish this homework? (Because you probably want to finish it.)

Jak mówić po rosyjsku? How do I speak Russian? (Because you want to speak it repeatedly, continuously, not say one single thing.)

Modal verbs: can you do this?

When combined with modal verbs like can, want to, must, etc, you’ll have to consider your context as well.

Muszę zrobić pracę domową. I have to finish my homework. (Not just casually do it, but finish the whole thing.)

Co muszę robić w szkole? What do I have to do in school? (It’s a lot of things, not just one task.)

Chcę zjeść coś. I want to eat something. (Because you want to eat the whole ‘something’, in order to feel full.)

Chcę robić coś interesującego. I want to do something interesting. (It doesn’t matter whether you finish it; you just want to do something.)

Mogę ci pomóc. I can help you (with a thing). (I am able to successfully help you with this task.)

Mogę ci pomagać. I can help you (repeatedly/generally). (I can help you with many things, many times.)

Umiem czytać. I can read. (imperfective because it is a skill, not a task.)

Negatives: I didn’t do this

Negative perfective verbs (on their own or combined with auxiliaries above) mean that you started something, but didn’t finish. E.g. you might have failed.

Nie zrobiłem pracy domowej wczoraj. I did homework yesterday, but didn’t finish it.

Nie muszę zrobić pracy. I don’t need to finish the entire work..

Negative imperfective verbs mean that you didn’t even start. You didn’t try, or you don’t want at all, you don’t have to do at all, etc.

Nie robiłem pracy domowej wczoraj. I didn’t do one bit of homework yesterday.

Nie chcę jeść. I don’t want to eat anything.

Nie muszę robić pracy. I don’t even have to do the work at all.

(Originally posted years ago on my own tumblr blog.)