The reflexive possessive svoj

English cannot tell you whose coat it is in Marko took his coat. It might be Marko's own coat, or the coat of some other man in the story. Serbian never leaves that open: it has a special possessive, svoj, which always points back to the subject of the clause. If the owner is the subject, you say svoj; if the owner is anybody else, you say njegov, njen, njihov and so on, exactly as before.

The one question to ask

Look at the verb, find its subject, and ask: does the thing belong to that subject? Yes → svoj. No → the ordinary possessive.

So njegov and njen now carry a hidden message: not the subject's. A Serbian speaker who hears Ana voli njenu sestru understands at once that the sister belongs to someone other than Ana.

The forms: svoj declines exactly like moj

There is nothing new to learn about the endings. svoj takes the same pronominal endings you already use for moj and tvoj, and like them it agrees with the thing owned, not with the owner. Because the owned thing is nearly always an object, the accusative column is the one you will use most.

The masculine accusative behaves as always: svoj for a thing (svoj kišobran), svog for a person or animal (svog dečka). The neuter accusative is svoje — the same as its nominative — and the plural accusative is svoje for masculine and feminine nouns, svoja for neuter ones, so svoja kola (kola, a car, is a neuter plural noun).

It works for every subject, singular or plural

The subject can be one person or a group; svoj still points to it. Deca vole svoje roditelje — the children love their own parents. Deca vole njihove roditelje would mean the children love some other people's parents.

Where svoj cannot go

• Not on the subject itself. In Njegov brat živi u Novom Sadu the brother is the subject, so there is nothing for svoj to point back to. Only the ordinary possessive is possible here.
• Not across a clause boundary. svoj looks at the subject of its own clause. In Sin ne zna gde je njegov novčanik the wallet is the subject of the little clause gde je ... novčanik, so it takes njegov even though it is the son's own wallet.
• Not after je meaning "this is". Ovo je moja torba — the subject is ovo, not the owner, so svoj has no place.

First and second person: a choice

When the subject is I, you or we, svoj can never be misunderstood, because moj already tells you who the owner is. Both Volim svoj posao and Volim moj posao are heard; svoj is the more careful, written choice. With a third-person subject — he, she, they, Marko, the children — there is no choice at all: svoj is obligatory for the subject's own things, and using njegov instead changes the meaning.

When you translate his, her or their, stop before you write njegov, njen or njihov and check the subject of the verb. If the subject is the owner, the word you need is a form of svoj. That single check is the whole rule.