Aktoren stiller spørsmålet.

Because Norwegian usually marks the by adding an ending to the noun.

• aktor = prosecutor
• aktoren = the prosecutor

So -en here is the definite singular ending, roughly like English the.

That is because spørsmål is a neuter noun.

• et spørsmål = a question
• spørsmålet = the question

For many neuter nouns, the definite singular ending is -et. So:

• aktor → aktoren
• spørsmål → spørsmålet

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

So instead of saying something like:

• the prosecutor
• the question

Norwegian commonly says:

• aktoren
• spørsmålet

That is one of the big differences from English. The noun ending often does the job that the does in English.

Here, stiller comes from å stille, and in this sentence it means asks or poses.

The expression å stille et spørsmål literally means to pose a question, but in natural English it is often just to ask a question.

So:

• stille et spørsmål = ask a question / pose a question

This is a very common fixed expression in Norwegian.

Norwegian can use both, but they are used a little differently.

• å stille et spørsmål = to ask a question
• å spørre = to ask

Examples:

• Aktoren stiller et spørsmål. = The prosecutor asks a question.
• Aktoren spør vitnet. = The prosecutor asks the witness.

So stille et spørsmål is especially common when the noun question is stated directly. Using spørre is also possible in some contexts, but stille et spørsmål sounds very natural here.

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

• subject + verb + object

So:

• Aktoren = subject
• stiller = verb
• spørsmålet = object

This matches standard English word order quite closely:

• The prosecutor asks the question

No. Norwegian verbs do not change for person the way English verbs sometimes do.

So you get:

• jeg stiller
• du stiller
• han stiller
• vi stiller

The verb form stays the same. That is much simpler than in English.

It looks similar, but here it does not mean a theater actor.

In Norwegian, aktor usually means prosecutor, especially in a legal setting.

If you want to say actor as in film or theater, Norwegian usually uses skuespiller.

So this is a useful false-friend warning:

• aktor = prosecutor
• skuespiller = actor

The ø sound does not exist in standard English, so it takes practice.

A rough guide:

• spør has a vowel somewhat like the vowel in British English bird, but with rounded lips
• må sounds a bit like mo in more, but longer
• let is a light ending

So spørsmålet is roughly pronounced like:

SPUR-shmoh-let

That is only an approximation, but it can help as a starting point. The most important part for English speakers is learning the rounded vowel ø.

The base forms are:

• aktoren → aktor
• stiller → å stille
• spørsmålet → spørsmål

So the sentence is built from:

• noun: aktor
• verb: å stille
• noun: spørsmål

This is useful because dictionaries usually list words under their base forms, not the inflected forms you see in the sentence.