Trećina, desetak, dvostruko: fractions, approximation, multiples

The second wave taught you to count; the eighth — to count people. This unit asks for something else: to say "a third", "about ten people", "twice as much". English does all of it with little closed sets; Serbian does it with exactly three suffixes. For example: “Трећина посла је готова, остатак радимо сутра” — A third of the work is done; we do the rest tomorrow. A rule from the Serbian course: worked out on…

Updated September 1, 2026 · Lingofly

How it works

The second wave taught you to count; the eighth — to count people. This unit asks for something else: to say "a third", "about ten people", "twice as much". English does all of it with little closed sets; Serbian does it with exactly three suffixes.

Fractions: the suffix -ina on an ordinal. Trećitrećina — a third, četvrtičetvrtina — a quarter, petipetina, desetidesetina. Half lives outside the row with its own word: polovina, or the short pola. After a fraction comes the of-form: trećina posla — a third of the work, četvrtina hleba — a quarter of the bread.

Approximation: the suffix -ak. Desetdesetak — about ten, petnaestpetnaestak, stostotinak — about a hundred, dvadesetdvadesetak. English rearranges the words ("some twenty people"); Serbian glues on a suffix and leaves the word order alone: petnaestak minuta.

Multiples: -struk and -struko. Dvostruk — double, dvostruko — twice as much, trostruk, trostruko — three times over, višestruk — multiple, višestruko — manifold, several times over. Past three, Serbs prefer pet puta više — five times more.

And the grand calque on which everyone stumbles. A change of size is introduced by the preposition za, not "by": cena je porasla za deset posto — the price rose BY ten percent, smanjili smo troškove za četvrtinu, novi motor je za red veličine tiši — an order of magnitude quieter. Saying it the English way outs you in the very first sentence.

Comparison: nego or od. Veći nego prošle godine — after nego stands the plain form. Veći od prošlogodišnjeg — after od stands the of-form. Both are right; do not mix them: "veći nego od" is not said.

Table

Trećina, desetak, dvostruko: fractions, approximation, multiples
what we sayhow it is builtexamplein English
a fractionordinal + -inatrećina, četvrtinaa third, a quarter
halfits own wordpolovina, polahalf
approximationnumber + -akdesetak, petnaestakabout ten, some fifteen
about a hundredsto + -inakstotinaka hundred or so
multiplesnumber + -strukodvostruko, trostrukotwice, three times over
several times overviše + -strukovišestruko manjeseveral times less
a change of sizeza + object formza deset postoby ten percent
comparisonnego + plain formveći nego lanebigger than last year

By example

  • Трећина посла је готова, остатак радимо сутра
    Trećina posla je gotova, ostatak radimo sutra
    A third of the work is done; we do the rest tomorrow
  • На састанку је било десетак људи, не више
    Na sastanku je bilo desetak ljudi, ne više
    There were about ten people at the meeting, no more
  • Цена је порасла за трећину и сада је двоструко већа него лане
    Cena je porasla za trećinu i sada je dvostruko veća nego lane
    The price rose by a third and is now twice what it was last year

How the rule settles in your head

A rule is not memorized from an explanation. It is memorized from an attempt to use it and a mistake — that is why the app delivers it mixed in with words, not as a separate lesson: it resurfaces exactly where you forgot it.

Frequently asked

Trećina, desetak, dvostruko: how does it work in Serbian?

The second wave taught you to count; the eighth — to count people. This unit asks for something else: to say "a third", "about ten people", "twice as much". English does all of it with little closed sets; Serbian does it with exactly three suffixes.

What does it look like in an example sentence Serbian?

“Трећина посла је готова, остатак радимо сутра” (Trećina posla je gotova, ostatak radimo sutra) — A third of the work is done; we do the rest tomorrow. A rule is easier to test on sentences like this than to memorize as a wording: what surfaces in conversation is the sentence.

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