Hilsenen er kort.

Because hilsenen is the definite singular form of hilsen.

• en hilsen = a greeting
• hilsenen = the greeting

In Norwegian, definiteness is often added to the end of the noun instead of using a separate word like the.

Here, hilsen is a common-gender noun, and its definite ending is -en. Since the noun already ends in -en, the result becomes hilsenen.

In Norwegian, the is usually built into the noun itself.

So instead of:

• English: the greeting

you often get:

• Norwegian: hilsenen

This is one of the biggest differences from English. Norwegian very often uses a suffix for definiteness:

• en bok = a book
• boken = the book

With hilsen, the same thing happens:

• en hilsen = a greeting
• hilsenen = the greeting

Er is the present tense of å være, which means to be.

So:

• er = is / am / are

Norwegian uses the same present-tense form for all persons:

• jeg er = I am
• du er = you are
• han/hun er = he/she is
• vi er = we are

In this sentence, Hilsenen er kort, it simply means The greeting is short.

Because kort is the adjective form used here, and with this noun it does not change.

A useful thing to know is that predicate adjectives in Norwegian often agree with the noun, but kort is one of those adjectives whose common-gender and neuter singular forms look the same.

Compare:

• en kort hilsen = a short greeting
• et kort brev = a short letter

In both cases, it stays kort.

But in the plural, it changes:

• korte hilsener = short greetings
• Hilsenene er korte = The greetings are short

Yes. In this sentence, kort is an adjective meaning short.

That matters because Norwegian kort can also be a noun:

• et kort = a card

But in Hilsenen er kort, the structure is:

• Hilsenen = subject
• er = verb
• kort = adjective describing the subject

So here it definitely means short, not card.

Normally, no. Hilsen er kort sounds incomplete or ungrammatical in ordinary Norwegian because hilsen is a countable noun, and singular countable nouns usually need some kind of determiner or definite marking.

Natural options are:

• En hilsen er kort. = A greeting is short.
• Hilsenen er kort. = The greeting is short.

So if you mean a specific greeting, hilsenen is the correct choice.

Yes, but the meaning changes.

• Hilsenen er kort = The greeting is short
  This refers to a specific greeting.

• En hilsen er kort = A greeting is short
  This sounds more general, or like you are talking about one greeting as an example.

So the original sentence is talking about a particular greeting, not greetings in general.

Yes. They are closely related.

• å hilse = to greet
• en hilsen = a greeting

So hilsen is a noun formed from the same idea as the verb å hilse.

You can think of it like this:

• å hilse = the action
• en hilsen = the greeting/message/result of that action

The word order here is very standard:

• Hilsenen = subject
• er = verb
• kort = subject complement/adjective

So the pattern is:

subject + verb + adjective

This is the normal order for a simple statement in Norwegian.

Also, Norwegian main clauses usually follow the verb-second rule, and this sentence does that naturally: the verb er comes in the second position.

A simple learner-friendly pronunciation would be something like:

HIL-se-nen er kort

A few notes:

• hilsenen has the stress on the first syllable: HIL-
• er is often pronounced quite lightly in everyday speech
• rt in kort can sound different from English r + t, especially in many Norwegian accents

You do not need perfect pronunciation right away, but saying it roughly as HIL-se-nen er kort will be understandable.