Two systems carry most of Russian grammar and neither of them is the cases. Aspect makes you say whether the thing got finished, in every past sentence, every future sentence and every infinitive. Verbs of motion make you say whether the going was in one direction or is what you generally do, before any prefix has been added. Both are compulsory, both start in week one, and no rule generates either of them from the English.
The absence of articles is the compensation and it is smaller than it sounds. Nothing has to be learned, and the work the and a were doing has moved into word order, where the thing already under discussion comes early and the new information comes last.
Six patterns to recognise on sight
- Я читал and Я прочитал, I was reading and I read it through. The aspect pair in the past, and the difference is whether the reading finished.
- идти and ходить, to go on one occasion and to go habitually. Verbs of motion split again on top of aspect, which is why they are a subject of their own.
- Я был and Я была, I was, said by a man and by a woman. The past tense agrees with the gender of the subject rather than with the person.
- Мне нравится, I like it, literally it is pleasing to me. The liker is in the dative and the thing liked is the subject.
- У меня есть, I have, literally at me there is. Russian has no ordinary verb for to have and builds it this way instead.
- Мне нужно, I need to. Another dative construction where English uses a subject, and this pattern covers a large set of everyday sentences.
Aspect is a claim about the outcome, not about the time
The pair is the vocabulary item. Читать and прочитать are one entry with two halves, and a card carrying only one of them will fail you the first time you try to say what you did yesterday. Sometimes a prefix makes the perfective, sometimes the stem changes, and sometimes the two words are unrelated, as говорить sits beside сказать, so the pairing has to be stored rather than derived.
Choosing between them is a judgement about what you are reporting. The perfective says a single event reached its end. The imperfective covers the process, the repetition, and the bare fact that something happened at all without any interest in whether it finished. That is why я читал эту книгу can mean you have had a go at the book, and я прочитал эту книгу means you got to the end of it.
Two structural consequences follow and both surprise people. The future is built two different ways: буду plus the imperfective, or the perfective's present forms used as a future, which means the perfective has no present tense at all. And under negation the imperfective is the usual choice, because a thing that did not happen did not reach an end either.
The imperfective becomes the default and stays there
Here is where Russian grammar stops developing. The imperfective is the dictionary form, it is what a learner meets first, and it is understood in almost every context where the perfective was wanted. So it becomes the default, the perfective is produced only when a teacher is listening, and a speaker can spend three years reporting completed events with the wrong half of every pair.
Nothing corrects it because both halves are real Russian and the sentence is grammatical. The exit is deliberate and narrow: take twenty things you did yesterday, say each one twice, once with each aspect, and say out loud what changed. Ten minutes a day for a fortnight builds the choice into the moment of speaking rather than into the moment of revision, and it is the kind of exercise worth taking to somebody who will interrupt, in what a teacher is worth, and what you can do alone.
Four verbs, two questions
The verbs of motion, before any prefix is added
These are not four words. They are one grid, and the second axis is a distinction English does not make anywhere.
One trip, one direction
- Я иду в магазин
- Я еду в Москву
Generally, or there and back
- Я хожу в школу
- Вчера я ходил в кино
- Я езжу на работу
The bottom row carries two meanings at once, the habitual and the there-and-back, and they are the same form. That is the cell that has no English equivalent, and it is why the grid has to be learned as a grid.
Two ways to find out which one a Russian would use
The Russian National Corpus is free and it is the instrument for a distinction no rule generates. Search a verb in both aspects and read fifty real sentences of each: the pattern is visible in the data long before it can be stated as a rule, and the data is what a native speaker's intuition is made of. It replaced asking somebody, which produces a confident answer and an explanation that is usually wrong.
A model is the second, used for one specific job rather than as a teacher. Give it your sentence and ask for the same sentence with the other aspect, then ask what each one now claims. It replaced waiting for a lesson to ask why the correction was a correction. Free at this level. The limitation is the usual one and it bites here: state a wrong rule with confidence and it will agree with you, so never ask which aspect is correct, ask what each of the two would mean.
The mistake: treating the motion verbs as vocabulary
Идти, ходить, ехать and ездить look like four words to be memorised and they are a two by two system. One axis is whether you are on foot or in something with wheels. The other is whether this is one trip in one direction or the kind of going you do generally, and that second axis has no English equivalent at all.
Learned as four words they never resolve, because the choice has to be made in the moment and there is nothing to reason from. Learned as a grid, with one example sentence in each cell, the system is an afternoon and the prefixes that multiply it afterwards are transparent. The prefixes also do two jobs at once, adding a direction and making the verb perfective, which is the join between this page and roots and prefixes that build whole families of words.
What grammar leaves to the endings
Every verb above still needs its subject and its object marked, and that marking is on the noun rather than in the word order, which is what each ending does, and which preposition demands it. Both aspects and all four motion verbs change their stress as they inflect, and the stress decides the vowels, which is stress that moves, and the vowels it reduces. And hearing which half of a pair somebody just used, at speed, with the ending reduced, is real speed, and the sounds that disappear in it.