Two hours, five hours: the Serbian numbers that rewrite the word behind them
One takes the plain nominative, two three and four take a form of their own, five and everything above it take the genitive plural - and eleven behaves like five, not like one. A Russian speaker already owns this system in outline and will still get it wrong, because Serbian draws two of the lines somewhere else.
The first sentence anybody actually needs in a Serbian café is an order for two coffees, and it is where the trouble starts. Two of them is две кафе. Five of them is пет кафа. The noun has changed its ending and nothing has happened to it except the number in front - you have not moved it into a case, you have not made it a subject or an object, you have simply counted higher.
This is not an irregularity to be memorised word by word. It is a system with three slots and two exceptions, and it is worth twenty minutes of attention because every noun in the language runs through it and it never changes shape.
One, a few, many
The first slot is one, and anything ending in one except eleven. The noun stays in the plain nominative singular, and the numeral itself agrees with it in gender the way an adjective would - so it has three shapes and you have to pick one.
The second slot is two, three and four, plus every compound number ending in them except twelve, thirteen and fourteen. Here the noun goes into a form of its own, the counting form - grammars call it бројна форма. For masculine and neuter nouns it looks exactly like the genitive singular; for feminine nouns it looks exactly like the nominative plural. It is neither of those things historically: it is what is left of the dual, the number Slavic once used for pairs, and the numbers two, three and four are precisely the ones small enough to have kept it.
The third slot is five and everything above it, and it also collects eleven through fourteen and every compound ending in them. The noun goes into the genitive plural and the numeral itself stops changing - from five upwards a numeral in this position is simply a word you put there. This is the slot that does most of the work, and it is the one to learn first.
| Number | With the noun |
|---|---|
| jedan | jedan sat |
| dva | dva sata |
| četiri | četiri sata |
| pet | pet sati |
| jedanaest | jedanaest sati |
| dvadeset jedan | dvadeset jedan sat |
| dvadeset dva | dvadeset dva sata |
Read the last two rows together. Twenty-one counts like one and twenty-two counts like two, because what decides the ending is the final digit and nothing else - with the single interruption of the teens, which all count like five however they end.
Čekam dva sata.
I have been waiting for two hours.
The counting form of a masculine noun, which looks like a genitive singular and is not one. Nothing here is genitive: the phrase is the object of the verb, and it would keep this shape as a subject too.
Pet minuta, ne više.
Five minutes, no more.
The trap for a Russian eye. минут is masculine, so this is its genitive plural - the reader who takes the word for a feminine singular «минута» sees a mistake where the grammar is correct.
Imam dve sestre i tri brata.
I have two sisters and three brothers.
One sentence, one slot, two different-looking endings: the feminine counting form coincides with the nominative plural, the masculine one with the genitive singular. Learn them as one rule with two faces, not as two rules.
Došla su dva studenta.
Two students arrived.
The dual leaves a second fingerprint, on the verb: with two, three or four the participle takes the ending it would have in the neuter plural. Say it a few times - the shape is fixed and it sounds wrong for about a week.
Došlo je pet studenata.
Five students arrived.
From five upwards the whole clause goes singular and neuter. The grammar has stopped seeing several people and started seeing one quantity - which is exactly what the genitive plural on the noun is saying as well.
Ovde živi dvadeset jedna osoba.
Twenty-one people live here.
Twenty-one counts like one all the way down: singular noun, singular verb, and the numeral agreeing in gender with a feminine noun. English has to say «people» here and Serbian must not.
What your Russian gets right, and the two places it does not
The architecture transfers completely. Russian splits its numerals in the same three places, keeps the teens with the large numbers in the same way, and puts the verb in the same singular after the big ones. A Russian speaker will produce the two central patterns correctly by instinct on the first day and should trust that instinct.
Two things do not transfer. The first is small and constant: in the counting form the two languages chose different endings for feminine nouns, so the Russian instinct produces an ending that is right in Russian and merely close in Serbian. It is the single commonest mistake Russian speakers make with Serbian numbers, and it survives years of otherwise fluent speech.
The second is a whole category Russian only half has. Alongside the ordinary numerals Serbian keeps a collective series (двоје, троје, четворо) used for mixed groups of people and for the young of anything, and a second series used only for groups of men - двојица and тројица and so on up. Russian has the first of those and nothing at all corresponding to the second, so this is the one part of the system that has to be learned rather than recognised.
U sobi je dvoje dece.
There are two children in the room.
Children take the collective, and the noun after it goes into the genitive plural regardless of how small the number is. Counting them with the ordinary numeral is understood and is not what a Serb says.
Ispred ulaza stoje dvojica policajaca.
Two policemen are standing in front of the entrance.
The men-only series. Swap it for the collective one and the sentence stops promising that both of them are men - which is information Serbian expects you to supply and English cannot carry without extra words.
Pozvao je petoro gostiju.
He invited five guests.
The collective runs upward as far as you need it. Using it here says the five guests are not all of one sex, and saying that is not optional politeness - the plain numeral would be read as a claim.
Do not learn this from the table. Pick one noun you say every day - the word for hour in the table above is the obvious candidate, because a clock gives you a reason to say it - and say the three slots out loud with it every time you check the time. The pattern is three items long. Once those three are automatic with one noun, every other noun in the language follows them without being learned separately.
One noun in that table has a second genitive plural, and the two are not interchangeable. сат means both an hour and the object on your wrist. Counted as hours it takes the form in the table; counted as watches and clocks it takes сатова instead. So a sentence about five of them is a sentence about time or a sentence about a shop window, and the ending is the only thing that says which.
None of this is a special corner of the grammar you can leave for later. Numbers are in the first conversation you have - a price, a platform, a time, an address, an age - and the counting form is the piece of Serbian that a learner uses most often on the day they learn it. It is also, unusually for this language, a rule with no exceptions worth listing beyond the two above.