Verbal aspect transfers almost for free from Russian - except for these two things
If you already think in perfective and imperfective, Serbian aspect is the smoothest part of the whole language for you. Two places still catch Russian speakers out: motion verbs, where Russian keeps a distinction Serbian gave up, and the handful of verbs where both languages use an unrelated word for the other half of the pair.
A learner arriving at Serbian aspect from English has to build an entirely new mental category from scratch: the idea that a verb's form itself, not just a tense marker, encodes whether an action is a single bounded event or an ongoing, repeated or general one. A learner arriving from Russian has already built that category, fully furnished, years ago. Almost everything about how Serbian aspect works - the two-way perfective/imperfective split, the fact that most verbs come in matched pairs, the way one member of the pair is usually formed by prefixing the other - is the same mental move you already make every time you choose between делал and сделал. This is the rare topic where the honest advice to a Russian speaker is: trust your instinct, it is very likely right.
What transfers essentially unchanged
The everyday mechanics repeat almost verb for verb. A prefix turns an imperfective verb perfective the same way in both languages, and for a good number of common, everyday verbs it is even the same prefix on a recognisably related root: read and see are the clearest cases, where the Serbian pair and the Russian pair line up prefix for prefix.
| Imperfective | Perfective |
|---|---|
| čitati | pročitati |
| pisati | napisati |
| gledati | pogledati |
| raditi | uraditi |
The present tense of an imperfective verb also does the same extra job in both languages: Serbian uses it for a scheduled near-future exactly the way Russian does, an imperfective present standing in for a planned, arranged future event rather than something happening this instant. If a rule about aspect already feels automatic to you in Russian, it is safe to assume it works the same way in Serbian until you hit specific evidence otherwise.
Where the instinct misfires: motion verbs
Russian keeps a second distinction layered on top of ordinary aspect for verbs of motion: идти against ходить, ехать against ездить, one member for a single trip in one direction, the other for round trips, habitual motion, or motion in no particular direction. Serbian never grammaticalised that same split to the same degree - for going on foot, there is essentially one core imperfective verb, ићи, covering both a single walk across the room right now and a habitual daily walk to work, with no separate lexical verb standing in for the second meaning the way ходить does in Russian.
This is the single most common import error motion verbs produce: a Russian speaker reaches for a mental slot that says "which of the two verbs do I need here", and Serbian only ever offers one to reach for. The fix is not a second verb to memorise - it is letting go of the question. Context, adverbs like сваки дан ("every day") or сад ("right now"), and ordinary aspect already say everything Russian's second verb used to say.
Where the instinct misfires: suppletive pairs do not match each other
A very small set of extremely common verbs in both languages form their aspect pair not by prefixing the same root, but by borrowing a completely unrelated verb for the other half - Russian's говорить pairs with сказать, a different root entirely, rather than with any prefixed form of говорить itself. Serbian does the same trick for the same verb - говорити pairs with рећи - but the two languages did not coordinate on which unrelated root to borrow. Knowing that Russian uses suppletion here tells you nothing about what Serbian's suppletive partner will be; it only tells you to expect one and go look it up rather than guess a prefix.
Keep the underlying logic - bounded single event versus ongoing, habitual or general one - on full autopilot; it is identical to Russian and second-guessing it will only slow you down. Spend your actual attention on two narrow lists instead: the handful of motion verbs where Russian's determinate/indeterminate split has no Serbian counterpart, and the handful of high-frequency suppletive pairs (start with говорити/рећи) that have to be memorised individually rather than derived.
Sutra idem u Beograd.
Tomorrow I'm going to Belgrade.
Imperfective present for a scheduled trip - the same logic Russian uses for завтра еду в Москву, just with Serbian's single verb standing in where Russian would use еду.
Svaki dan idem peške na posao.
Every day I walk to work.
Идем, the same verb a Serb uses for a single walk right now - no separate habitual verb the way Russian's хожу stands apart from иду.
Sad idem do prodavnice.
I'm going to the store right now.
The identical verb, идем, for the one-time trip Russian would mark with иду rather than хожу - same Serbian form, both meanings.
Reci mi istinu.
Tell me the truth.
The imperative of рећи, the suppletive perfective partner of говорити - a different root, just as сказать is a different root from говорить.