Questions & Answers about Knjiga koju tražim nije na polici u sobi.
Because koju is the accusative singular feminine form of the relative pronoun koji.
In Knjiga koju tražim..., the pronoun refers back to knjiga (book), so it must agree with knjiga in gender and number: feminine singular.
But its case is not chosen by knjiga. Its case depends on its role inside the relative clause:
- tražim koga/šta? = I am looking for what?
- answer: koju = which/that
So:
- knjiga = nominative, because it is the subject of the main sentence
- koju = accusative, because it is the object of tražim
That is why Serbian uses koju, not koja.
Koju introduces a relative clause, the part koju tražim = that I’m looking for.
So the structure is:
- Knjiga = the book
- koju tražim = that I’m looking for
Together:
- Knjiga koju tražim = The book that I’m looking for
English often uses that, , or even no pronoun at all: