Bibliotekar je u čitaonici.

• Bibliotekar = librarian. It is the subject of the sentence.
• je = is. This is the 3rd person singular present form of biti (to be).
• u = in.
• čitaonici = reading room in the locative case, used after u when talking about location.

So the structure is literally: Librarian is in reading-room.

Serbian has no articles, so it does not use separate words for a/an or the.

That means bibliotekar can mean:

• a librarian
• the librarian

Which one is meant depends on context.

Because after u meaning in/inside for a location, Serbian normally uses the locative case.

The basic form is:

• čitaonica = reading room

But after u for location, it becomes:

• u čitaonici = in the reading room

So čitaonici is the locative singular form of čitaonica.

No. u can take different cases depending on meaning.

• u + locative = location, meaning in/at
  • u čitaonici = in the reading room
• u + accusative = motion into something
  • u čitaonicu = into the reading room

So in this sentence, u čitaonici shows where someone is, not where they are going.

In this kind of sentence, je is normally used because Serbian needs the present-tense form of to be here.

So:

• Bibliotekar je u čitaonici. = correct standard sentence

Leaving out je would sound incomplete in standard Serbian.

Yes. Serbian word order is more flexible than English word order because cases help show the role of words.

These are all possible, depending on emphasis:

• Bibliotekar je u čitaonici.
• U čitaonici je bibliotekar.
• Je bibliotekar u čitaonici? (less neutral, often in certain styles or speech)

The most neutral version here is:

• Bibliotekar je u čitaonici.

Yes, bibliotekar is a masculine noun.

A feminine form is:

• bibliotekarka = female librarian

So you could also say:

• Bibliotekarka je u čitaonici. = The female librarian is in the reading room.

A helpful rough guide is:

• č sounds like ch in church
• ć is softer than č, but there is no ć in this word
• čitaonici is roughly: chee-tah-oh-nee-tsee

Breaking it down:

• či
• ta
• o
• ni
• ci

Also:

• c in Serbian sounds like ts
• so the ending -ci sounds like tsee

The dictionary form is:

• čitaonica

This is the nominative singular form, the form you would usually find in a vocabulary list or dictionary.

In the sentence, it changes to:

• čitaonici because it is in the locative singular

Usually it means in the reading room, but in natural English translation it can sometimes be rendered as at the reading room depending on context.

The Serbian phrase u čitaonici strongly suggests being physically inside that place.

A very common way is just to use intonation in speech:

• Bibliotekar je u čitaonici?

In writing, you add a question mark.

You can also ask more explicitly:

• Da li je bibliotekar u čitaonici? = Is the librarian in the reading room?

This is a very common yes/no question pattern in Serbian.

The negative of je is nije.

So:

• Bibliotekar nije u čitaonici. = The librarian is not in the reading room.

This is the standard negative form.

Not exactly.

• biblioteka = library
• čitaonica = reading room

A čitaonica may be a room inside a library or another place meant for reading/studying.

So:

• u biblioteci = in the library
• u čitaonici = in the reading room

Bibliotekar is in the nominative singular because it is the subject of the sentence.

So the case pattern is:

• bibliotekar = nominative singular
• čitaonici = locative singular

That is a very common Serbian sentence pattern:

• subject in nominative + je + location with a preposition