Hun ringer klienten.

Because klienten is the definite singular form: the client.

In Norwegian, the definite article is usually attached to the end of the noun:

• en klient = a client
• klienten = the client

So Hun ringer klienten means She is calling the client / She calls the client, not a client.

In Norwegian, the is often built into the noun itself as a suffix.

Here:

• klient = client
• klienten = the client

This is very common in Norwegian. English uses a separate word (the), but Norwegian often adds -en, -a, or -et to the noun, depending on the noun’s gender and form.

Ringer is the present tense of å ringe (to call / to ring).

So:

• å ringe = to call
• ringer = calls / is calling

In Norwegian, the present tense is often made by adding -r to the infinitive:

• snakke → snakker
• kjøpe → kjøper
• ringe → ringer

It can mean both, depending on context.

Hun ringer klienten can mean:

• She calls the client
• She is calling the client

Norwegian present tense often covers both the simple present and the present progressive from English. Context usually makes it clear.

Because Norwegian verbs do not change according to the subject the way English verbs sometimes do.

In English:

• I call
• you call
• she calls

In Norwegian, the verb stays the same:

• jeg ringer
• du ringer
• hun ringer

So ringer is used with all persons in the present tense.

This is the normal Norwegian main-clause word order:

subject + verb + object

So:

• Hun = subject
• ringer = verb
• klienten = object

That matches normal English word order in a sentence like She calls the client.

Usually, yes. Hun is the third-person singular pronoun for a female person:

• hun = she

Object form:

• henne = her

So:

• Hun ringer klienten = She is calling the client
• Klienten ringer henne = The client is calling her

No, not here.

In this sentence, klienten is a direct object, so Norwegian simply says:

• Hun ringer klienten

This is the most straightforward way to say She calls/is calling the client.

A learner may expect a preposition, but it is not necessary here.

Klient is normally a common gender noun in Bokmål:

• en klient
• klienten

That matters because the definite singular ending depends on gender. For common gender nouns, the ending is often -en.

For example:

• en bil → bilen
• en klient → klienten

A simple learner-friendly approximation is:

RING-er

A few useful notes:

• The r is pronounced clearly.
• The ng in ringer is like the ng in English sing.
• The ending -er is usually pronounced lightly.

So the whole sentence sounds roughly like:

hoon RING-er klee-EN-ten

That is only an approximation, but it can help at the beginner stage.

Yes. The verb å ringe can also relate to ringing in the sense of making a ringing sound, depending on context.

For example:

• Telefonen ringer. = The phone is ringing.

But in Hun ringer klienten, the meaning is clearly She is calling the client.

It can describe either one.

Depending on context, Hun ringer klienten could mean:

• something happening now: She is calling the client
• a habitual/repeated action: She calls the client

If you want to make the meaning clearer, Norwegian usually relies on extra context or time words, not a different present-tense form.