Bavim se sportom: the with-case that holds half the unit

The with-case is a thing English keeps in prepositions — "with a knife", "by bus" — and Serbian keeps in endings, which is why it hides inside half the sentences of this unit. For example: “Чиме се бавите? Бавим се спортом и предајем у школи” — What do you do? I do sports and teach at a school. A rule from the Serbian course: worked out on examples, not memorized as a wording.

Updated September 1, 2026 · Lingofly

How it works

The with-case is a thing English keeps in prepositions — "with a knife", "by bus" — and Serbian keeps in endings, which is why it hides inside half the sentences of this unit.

The endings. Masculine and neuter take -om, or -em after a soft stem: autobusom, vozom, nožem — with a knife, mužem — with the husband. A feminine word in -a takes -om: rukom — by hand, olovkom — with a pencil. A feminine word on a consonant takes -i or -ju: stvari, krvlju. The plural is the same for everyone: -ima or -amaautobusima, knjigama.

Rule one: what you do it with — no preposition. Pišem olovkom — I write with a pencil, idem autobusom — I go by bus, sečem nožem — I cut with a knife. The preposition sa here is not just redundant, it changes the meaning: idem sa drugom — with a friend, idem autobusom — by bus. English draws the same line between "with" and "by"; Serbian draws it with a preposition against an ending.

Rule two: a handful of frequent verbs demand the with-case and nothing else. Baviti se (to do, to be into) — bavi se sportom, bavi se muzikom — and the same verb asks "what do you do for a living": čime se bavite? — literally "with what are you occupied". Rukovoditirukovodi timom — he runs a team. Upravljatiupravlja firmom. Vladativlada jezikom — he masters the language, literally rules it. The list is short; learn it whole.

Rule three — the one English gets wrong first: after "to be" a profession stands in the plain form, not the with-case. English "he was a mechanic" keeps the noun flat, and Serbian agrees: on je bio mehaničar. The with-case here sounds like homework. But postati (to become) allows both: postao je mehaničar and postao je mehaničarem — the first is twice as common.

And the spot where Serbian is wider than English: the with-case also covers time and path. Danima — for days, noću — at night, nedeljom — on Sundays, šumom — through the forest. Hence radimo subotom — we work on Saturdays — and by no means "we work with Saturday".

Table

Bavim se sportom: the with-case that holds half the unit
the wordthe with-formin the sentencein English
autobusautobusomidem autobusomI go by bus
sportsportombavim se sportomI do sports
timtimomrukovodi timomhe runs a team
firmafirmomupravlja firmomshe runs a company
stvarstvariradi sa tom stvarihe works with that thing
kolegekolegamarazgovaram sa kolegamaI talk with colleagues
subotasubotomradimo subotomwe work on Saturdays
mehaničarmehaničarbio je mehaničarhe was a mechanic

By example

  • Чиме се бавите? Бавим се спортом и предајем у школи
    Čime se bavite? Bavim se sportom i predajem u školi
    What do you do? I do sports and teach at a school
  • На посао идем аутобусом, а са колегом се видим средом
    Na posao idem autobusom, a sa kolegom se vidim sredom
    I take the bus to work, and I meet a colleague on Wednesdays
  • Отац је био механичар, а брат је постао електричар
    Otac je bio mehaničar, a brat je postao električar
    My father was a mechanic, and my brother became an electrician

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

Bavim se sportom: how does it work in Serbian?

The with-case is a thing English keeps in prepositions — "with a knife", "by bus" — and Serbian keeps in endings, which is why it hides inside half the sentences of this unit.

What does it look like in an example sentence Serbian?

“Чиме се бавите? Бавим се спортом и предајем у школи” (Čime se bavite? Bavim se sportom i predajem u školi) — What do you do? I do sports and teach at a school. 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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