koji vs što (relative 'which/that') | Serbian Grammar

Serbian has two major relative strategies. Inflected који simultaneously links the clause and marks the antecedent's gender, number, and role inside the relative clause. Invariant што merely links; with a concrete antecedent in a non-subject role, another pronoun normally resumes that role. English who, which, and that conceal much of this architecture.

The neutral default for a concrete noun in careful Serbian is који. Што is especially natural after broad words such as све, оно, нешто and as a link to an entire preceding proposition; with concrete nouns it is commoner in conversation and informal narrative. The full који paradigm is on the relative-pronoun page; this guide is about choosing the strategy.

The decision tree

Is the antecedent све, оно, нешто, ништа, то, or a whole preceding statement? Choose invariant што.
Is the antecedent a concrete noun in neutral or formal prose? Choose inflected који.
Is this informal speech with a concrete antecedent? Што is possible. If the antecedent is the relative-clause subject, no resumptive pronoun is needed.
Does that concrete antecedent have another role inside a што clause? Express the role again: a clitic for accusative/dative/genitive where available, or a preposition plus full pronoun.
Would the clause have to show a preposition or an unambiguous case relation? Који is usually clearer and stylistically safer.

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With који, one form does both jobs: link + case role. With concrete-noun што, split those jobs: што links, while га/јој/с њим resumes the antecedent.

Concrete nouns: који is the neutral default

Који agrees with the antecedent in gender and number, but its case comes from its job inside the relative clause.

Пронашли смо сведокињу која је видела цео догађај.

We found the witness who saw the entire incident.

Пронашли смо сведокињу коју је полиција већ саслушала.

We found the witness whom the police had already questioned.

The antecedent remains feminine singular, but nominative која is subject of видела, while accusative коју is object of саслушала.

Ово је саветник с којим смо јутрос разговарали.

This is the adviser we spoke with this morning.

Serbian places с before instrumental којим. It does not strand the preposition at the end as conversational English can.

Broad antecedents: што is the natural choice

After semantically broad neuter expressions, invariant што is not an informal substitute—it is the ordinary strategy.

Све што сте навели у пријави мора бити тачно.

Everything you stated in the application must be accurate.

Показаћу ти нешто што још нико није видео.

I'll show you something that no one has seen yet.

Оно што ме највише брине јесте недостатак времена.

What worries me most is the lack of time.

There is no gender-and-case paradigm to compute here. Што remains unchanged because it packages the broad content rather than agreeing like an adjective.

Што can refer to a whole proposition

When the antecedent is the preceding situation rather than one noun, што is required.

Воз је поново каснио, што је изнервирало путнике.

The train was late again, which annoyed the passengers.

Here што refers to the fact that the train was late. Који would seek a noun with matching gender and number and would therefore create the wrong attachment.

Concrete noun + што: register and resumption

With a concrete noun, subject што relatives occur in conversation and informal narrative. They are standardly understood but less neutral than који in edited expository prose.

Знаш ли оног момка што свира виолину испред позоришта?

Do you know that guy who plays the violin outside the theater? (informal)

The understood antecedent is subject of свира, so no extra subject pronoun is needed. The neutral edited alternative is момка који свира.

If the antecedent is an object or recipient, што cannot show that role. A resumptive pronoun supplies it.

Где је кабл што сам га јуче оставила поред монитора?

Where is the cable that I left beside the monitor yesterday? (informal; female speaker)

То је мајстор што му увек верујем кад процењује квар.

That is the repairman whom I always trust when he assesses a fault. (informal)

Accusative га resumes кабл; dative му resumes мајстор because веровати governs dative. In neutral edited Serbian, prefer кабл који сам оставила and мајстор којем верујем.

After a preposition, use a full resumptive form rather than a clitic:

То је колегиница што сам с њом водила пројекат прошле године.

That is the colleague I ran a project with last year. (informal; female speaker)

The neutral alternative is колегиница с којом сам водила пројекат. The construction што...с њом divides the link and case role across two elements.

Minimal pairs: same referent, different strategy

Позови преводиоца којег смо ангажовали за конференцију.

Call the translator whom we hired for the conference. (neutral across registers)

Позови преводиоца што смо га ангажовали за конференцију.

Call the translator whom we hired for the conference. (informal/conversational)

The truth conditions are the same. The first concentrates relative marking in accusative којег; the second uses invariant што plus accusative га.

Узео је све што му је било потребно.

He took everything he needed.

Replacing this broad-antecedent што with a casually chosen form of који is not an equivalent stylistic upgrade. The antecedent type itself favors што.

Information structure and punctuation

The choice of који or што does not decide whether the clause is restrictive. Either strategy can identify a subset; commas depend on whether the clause restricts or merely adds information.

Рачуни који су плаћени означени су зеленом бојом.

The invoices that have been paid are marked in green.

Овај рачун, који је већ плаћен, не треба поново слати.

This invoice, which has already been paid, should not be sent again.

For attachment and comma logic, continue with relative clauses in depth.

Diagnostic exercise

Task 1: Identify the antecedent type

оно што смо договорили — уговор који смо потписали — уговор што смо га потписали

what we agreed — the contract that we signed (neutral) — the contract that we signed (informal). Answer: broad што; concrete inflected који; concrete што + resumptive га.

Task 2: Rebuild the case role

човек којем сам послао поруку → човек што сам му послао поруку

the man to whom I sent a message → the man that I sent a message to. Answer: dative којем becomes resumptive му in the informal што strategy. (male speaker)

Common Mistakes

Omitting resumption with an object

❌ То је кључ што сам заборавио у колима.

Incorrect for the intended concrete-object што strategy—the object role requires resumptive га.

✅ То је кључ што сам га заборавио у колима.

That is the key I left in the car. (informal; male speaker)

Adding a resumptive object after који

❌ То је кључ који сам га заборавио у колима.

Incorrect neutral strategy—accusative који already fills the object role, so га duplicates it.

✅ То је кључ који сам заборавио у колима.

That is the key I left in the car. (male speaker)

Using који after a broad antecedent

❌ Ништа које сте предложили није прихваћено.

Incorrect after broad ништа—use invariant што, not an agreeing form of који.

✅ Ништа што сте предложили није прихваћено.

Nothing you proposed was accepted.

Using који for a whole preceding proposition

❌ Отказали су лет, који нас је све изненадио.

Wrong for the intended meaning ‘the cancellation surprised us’—који attaches to masculine лет and makes the flight itself the surprising entity.

✅ Отказали су лет, што нас је све изненадило.

They canceled the flight, which surprised all of us.

Key Takeaways

Use који as the neutral concrete-noun strategy; it expresses agreement and internal case.
Use што naturally after све, оно, нешто, ништа and for a whole preceding proposition.
Concrete-noun што is especially conversational; non-subject roles require resumption.
Do not combine inflected који with a duplicate resumptive clitic.
Register, antecedent type, and the role inside the relative clause—not the English word that—determine the choice.

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