Filmen handler om cowboyen.

They mark the noun as definite singular, which is usually the equivalent of English the.

• film = film / movie
• filmen = the film / the movie
• cowboy = cowboy
• cowboyen = the cowboy

In Norwegian, the definite article is often attached to the end of the noun instead of being a separate word.

Because Norwegian usually puts definiteness on the noun itself.

Compare:

• en film = a film
• filmen = the film
• en cowboy = a cowboy
• cowboyen = the cowboy

So in this sentence, filmen and cowboyen already include the idea of the.

Handler om means is about or deals with.

So:

• Filmen handler om cowboyen = The film is about the cowboy

This is an idiomatic expression. Even though English handle looks similar, this Norwegian verb phrase does not mean to touch/manage physically here.

Yes. Handler is the present tense form.

The infinitive is:

• å handle om = to be about / to deal with

A simple pattern is:

• å handle om = infinitive
• handler om = present tense

So Filmen handler om cowboyen is in the present tense: The film is about the cowboy.

Because handle takes the preposition om when it means to be about.

So you learn it as a unit:

• å handle om = to be about

This is very common in Norwegian: the verb and preposition belong together. It is usually best to memorize the whole expression, not just the verb by itself.

This is the normal word order for a basic Norwegian main clause:

• subject + verb + rest

So here:

• Filmen = subject
• handler = verb
• om cowboyen = prepositional phrase

Norwegian also follows the V2 rule in main clauses, which means the finite verb is in the second position. In this sentence, that happens naturally because the subject comes first.

Yes. Cowboyen means the cowboy, so it refers to a specific or identifiable cowboy.

If you wanted to say a cowboy, you would say:

• Filmen handler om en cowboy = The film is about a cowboy

So the difference is:

• cowboyen = the cowboy
• en cowboy = a cowboy

Yes, they are used in Norwegian.

• film is a normal Norwegian word.
• cowboy is a loanword from English, but it is also used in Norwegian.

Even when a word comes from English, Norwegian grammar still applies to it, which is why you get forms like:

• en cowboy
• cowboyen

Yes. In everyday English, film and movie are often different word choices, but Norwegian film can correspond to either film or movie depending on context.

So Filmen handler om cowboyen could naturally be translated as either:

• The film is about the cowboy
• The movie is about the cowboy

They are treated as common gender nouns in Bokmål, which is why they take:

• en in the indefinite singular
• -en in the definite singular

So:

• en film → filmen
• en cowboy → cowboyen

For a learner, the important thing here is that both nouns follow the common en / -en pattern.