Hun rapporterer ulykken.

Because ulykken is the definite singular form of the noun.

• en ulykke = an accident
• ulykken = the accident

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

So:

• Hun rapporterer ulykken = She reports the accident

The -er ending here marks the present tense of the verb å rapportere (to report).

So:

• å rapportere = to report
• rapporterer = report / reports / am reporting / is reporting / are reporting, depending on context

Norwegian present tense does not change for different subjects:

• jeg rapporterer = I report
• du rapporterer = you report
• hun rapporterer = she reports

Unlike English, the verb form stays the same.

In Norwegian, definiteness is often built into the noun itself.

English uses:

• the accident

Norwegian usually uses:

• ulykken

That final -en acts like the for many masculine nouns.

So instead of a separate article before the noun, Norwegian often adds the definite ending directly to the noun.

Hun is the subject form, so it means she.

Compare:

• hun = she
• henne = her

In this sentence, hun is doing the action, so the subject form is needed:

• Hun rapporterer ulykken = She reports the accident

If she were the object, you would use henne instead.

Yes, in this sentence the basic word order is very similar to English:

• Hun = subject
• rapporterer = verb
• ulykken = object

So the structure is:

Subject + Verb + Object

That is the normal word order in a simple Norwegian main clause.

Yes. Norwegian present tense often covers both:

• she reports
• she is reporting

So Hun rapporterer ulykken could mean either, depending on context.

Norwegian does not always make the same present simple vs. present continuous distinction that English does.

Ulykke is usually a masculine noun:

• en ulykke
• ulykken

In Bokmål, many feminine nouns can also be treated as masculine, and learners often see that in practice. The important thing in this sentence is recognizing the pattern:

• indefinite: en ulykke
• definite: ulykken

Yes, gender matters because it affects articles and endings.

You would usually say:

• Hun rapporterte ulykken. = She reported the accident.

Here:

• rapporterer = present
• rapporterte = past

So the verb changes, but the rest of the sentence can stay the same.

Not always. Rapportere is a real and correct verb, but in some everyday situations Norwegians might also use other expressions depending on context, such as reporting something to the police, to a boss, or in a formal system.

For example, in some contexts you might also hear verbs related to reporting, notifying, or filing a report.

Still, Hun rapporterer ulykken is grammatically clear and understandable.

A learner may find ulykken tricky because of the y sound.

Roughly:

• u-lyk-ken

A few notes:

• y in Norwegian is not like English y in yes
• it is a vowel sound with no exact English equivalent
• the kk makes the consonant sound short and firm
• the final -en is the definite ending

The best way to learn it is by listening to native audio and repeating, especially the vowel in ly.