Film je zabavan.

Je is the present-tense form of biti (to be) for he/she/it is.

So the sentence is literally structured like:

• Film = film / movie
• je = is
• zabavan = entertaining / fun

In Serbian, you normally do use the verb to be in sentences like this. Unlike in some Slavic languages, you cannot usually leave it out in standard Serbian.

Because adjectives in Serbian must agree with the noun they describe.

Here, film is:

• masculine
• singular
• nominative

So the adjective also has to be masculine singular nominative:

• zabavan

Compare:

• Film je zabavan. = The film is entertaining.
• Knjiga je zabavna. = The book is entertaining.
  (knjiga is feminine, so zabavna)
• Dete je zabavno. = The child is entertaining / fun.
  (dete is neuter, so zabavno)

Yes. Film is a masculine noun in Serbian.

A very common clue is that many masculine nouns in the dictionary form end in a consonant, and film does.

Because it is masculine, related words must match it:

• ovaj film = this film
• dobar film = a good film
• Film je zabavan. = The film is entertaining

Serbian does not have articles like English a/an and the.

So Film je zabavan can mean:

• The film is entertaining
• A film is entertaining
• This film is entertaining

Which meaning is intended depends on context.

If you want to make it more specific, Serbian often uses demonstratives such as:

• Ovaj film je zabavan. = This film is entertaining.
• Taj film je zabavan. = That film is entertaining.

Yes, Serbian word order is more flexible than English, but not completely free.

The neutral, most straightforward order is:

• Film je zabavan.

You can also say:

• Zabavan je film.

This can sound more emphatic, as if highlighting zabavan.

One important rule: je is a clitic, which means it usually goes in the second position of the sentence or clause. So you should pay attention to where je can stand.

In standard Serbian, that would normally sound incomplete or unnatural as a full sentence.

You usually need:

• Film je zabavan.

Omitting je may happen in headlines, notes, poetry, or very special styles, but not in normal everyday standard speech.

A simple English-friendly approximation is:

• zah-BAH-vahn

A few helpful points:

• z is like English z
• a is a clear ah sound
• stress is roughly on the middle syllable: za-BA-van

Also, Serbian spelling is very phonetic, so words are usually pronounced much like they are written.

Not exactly. Zabavan usually means:

• fun
• entertaining
• enjoyable

If you want to say funny in the sense of making you laugh, Serbian often uses:

• smešan

So:

• Film je zabavan. = The film is entertaining / fun.
• Film je smešan. = The film is funny.

Sometimes there can be overlap, but they are not the same basic meaning.

This is a very common question.

• zabavan = fun, entertaining
• zanimljiv = interesting

So:

• Film je zabavan. = The film is fun / entertaining.
• Film je zanimljiv. = The film is interesting.

A movie can be:

• zabavan but not very deep
• zanimljiv but not especially fun
• both zabavan i zanimljiv

It is in the nominative singular.

That is because film is the subject of the sentence:

• Film je zabavan.

In dictionary form, nouns are normally given in the nominative singular, so film is also the basic form you would look up.

The main thing that changes is the adjective, because it must agree with the noun.

Examples:

• Film je zabavan.
  masculine singular

• Serija je zabavna.
  feminine singular

• Pismo je zabavno.
  neuter singular

• Filmovi su zabavni.
  masculine plural

Notice that the verb changes too:

• singular: je = is
• plural: su = are

Yes, film is the normal everyday Serbian word for film/movie.

Depending on context, people may also say:

• film = film, movie
• filmovi = films, movies

So this sentence sounds completely natural:

• Film je zabavan.

Yes. In everyday Serbian, film commonly refers to a movie in general.

So Film je zabavan is a natural way to say that a movie is entertaining. English may distinguish film and movie more depending on style, but Serbian film covers that everyday meaning well.