Relative pronoun koji as clause subject

In short

koji = who / which / that, agreeing with the noun before it (nominative, as subject of its clause):

	sg	pl
m	koji	koji
f	koja	koje
n	koje	koja

Never omitted; sits right after its noun; clitics follow it (koja se zove). Gender from the antecedent, case from the clause: ženu koja radi.

A2 · Lesson 21 · Relative clauses with koji as subject

The full explanation, from the lesson that teaches this rule

So far every sentence you have built has had one verb. Now you can put two together: Komšija stanuje na trećem spratu. Komšija je lekar. — two short facts about the same man. Serbian lets you glue them into one sentence, just as English does with who or which: Komšija koji stanuje na trećem spratu je lekar. — "The neighbour who lives on the third floor is a doctor."

The little word doing the gluing is koji. It opens the second clause, points back at the noun just before it (its antecedent), and takes over that noun's job inside the clause. In this lesson it is always the subject of its clause — the one doing the living, working, talking — so it remains in the nominative. What changes is its ending.

koji agrees with the noun it points back to

koji behaves exactly like an adjective in the nominative: it takes the gender and number of its antecedent. You already know these endings from dobar / dobra / dobro and the plural dobri / dobre / dobra — koji takes the same ones.

The nominative forms of koji. Compare dobar, dobra, dobro / dobri, dobre, dobra.
Antecedent	koji	Example
masculine singular	koji	komšija koji radi noću — the neighbour who works nights
feminine singular	koja	žena koja živi preko puta — the woman who lives across the road
neuter singular	koje	dete koje se igra u dvorištu — the child who is playing in the yard
masculine plural	koji	ljudi koji stanuju iznad nas — the people who live above us
feminine plural	koje	komšinice koje piju kafu — the neighbours (women) who are drinking coffee
neuter plural	koja	deca koja se igraju napolju — the children who are playing outside

Watch the nouns whose ending lies about their gender. komšija ends in -a but is a man, so in the singular it takes koji: komšija koji. In the plural, though, komšije takes the -e form like any noun in -a: komšije koje me pozdravljaju. deca (children) looks like a feminine singular but is treated as neuter plural — deca koja se igraju. ljudi (people) is masculine plural — ljudi koji.

What decides the ending: the antecedent, not the main clause

The ending of koji is decided by ONE thing: the noun it points back to. It does not matter what the rest of the main sentence is doing. In Poznajem ženu koja radi u apoteci ("I know the woman who works at the pharmacy") the woman is the object of poznajem, so she is in the accusative ženu — but inside her own little clause she is the one working, so it is koja, nominative feminine. Look left for the gender and number; look inside the clause for the case.

Two things English lets you skip and Serbian does not

koji is never left out. English says the man that lives here or just the man living here. Serbian always says čovek koji živi ovde. There is no shortcut.
There is always a comma before the clause when it adds extra information about something already identified: Moja komšinica, koja je vrlo ljubazna, uvek me pozdravi. When the clause is what identifies the noun — the neighbour who lives on the third floor (as opposed to some other neighbour) — the comma is left out. If in doubt at this level, no comma for identifying clauses, comma for asides.

Where the clause goes

The koji-clause sits directly after its antecedent, even if that splits the main sentence in two: Momak koji stanuje pored nas svira gitaru. — "The guy who lives next to us plays the guitar." The main verb svira has to wait until the clause is finished. This feels odd at first; read it as the English The guy — who lives next to us — plays the guitar.

Because the koji-clause is a clause of its own, its clitics obey second position inside it: žena koja se zove Vesna, komšija koji me uvek pozdravi. The clitic comes right after koji.

In this lesson koji is always the one DOING something in its clause. "The neighbour whom I greet" — where koji would be the object — is the next lesson. If your English sentence has who or which followed straight by a verb, you are on safe ground here.

Check what you read

6 of the 16 questions this lesson asks in the app. Type the form or pick the answer.

Komšija ___ stanuje na trećem spratu je lekar.
Žena(koji) živi preko puta radi u apoteci.
Dete(koji) se igra u dvorištu ima pet godina.
Ljudi ___ stanuju iznad nas prave buku.
Komšinice(koji) piju kafu ispred zgrade mnogo pričaju.
Imam komšiju ___ svaki dan trči u parku.

Examples from the course

The marked word is where the rule applies. Press play to hear the sentence.

Poznajem ženu koja radi u apoteci.
I know the woman who works at the pharmacy.
Deca koja se igraju napolju mnogo viču.
The children who are playing outside shout a lot.
Ljudi koji stanuju iznad nas prave buku.
The people who live above us make noise.
Komšinice koje piju kafu ispred zgrade mnogo pričaju.
The neighbours (women) who drink coffee in front of the building talk a lot.
Devojka koja stanuje na prvom spratu studira medicinu.
The girl who lives on the first floor studies medicine.
Žene koje sede na klupi ogovaraju nove stanare.
The women who are sitting on the bench are gossiping about the new residents.
Stanari koji su se iselili nisu platili stanarinu.
The tenants who moved out didn't pay the rent.
Volim komšije koje me uvek pozdrave na stepenicama.
I like the neighbours who always greet me on the stairs.
Žena koja živi preko puta radi u apoteci.
The woman who lives across the road works at the pharmacy.
Dete koje plače cele noći smeta svim stanarima.
The child who cries all night bothers all the residents.