Questions & Answers about Ona čita knjigu u sobi.
Because knjiga is the dictionary form, or nominative form, meaning book.
In this sentence, book is the direct object of čita (reads), so Serbian uses the accusative case. For a feminine singular noun like knjiga, the accusative ending is -u:
- knjiga = nominative
- knjigu = accusative
So:
- Ona čita knjigu. = She is reading a/the book.
Because after u meaning in, Serbian uses the locative case when talking about a location.
So:
- soba = room (nominative)
- u sobi = in the room (locative)
This is a very common pattern:
- u školi = in school
- u kući = in the house
- u sobi = in the room
Ona is in the nominative case because it is the subject of the sentence.