Platesamleren bruker hodetelefonene.

In Norwegian, definiteness is often shown by adding an ending to the noun instead of using a separate article.

So:

• platesamler = record collector
• platesamleren = the record collector

and

• hodetelefoner = headphones
• hodetelefonene = the headphones

That means Norwegian can express the with the endings -en and -ene here, so no separate word is needed.

The ending -en is the definite singular ending for many common-gender nouns in Bokmål.

Here the noun is:

• en platesamler = a record collector
• platesamleren = the record collector

So -en is doing the job that English does with the.

Because hodetelefonene is a definite plural form.

The pattern is:

• en hodetelefon = a headphone
• hodetelefonen = the headphone
• hodetelefoner = headphones
• hodetelefonene = the headphones

So -ene marks the + plural.

Yes, Norwegian does have the singular en hodetelefon, but just like English, people often talk about headphones as a pair, so the plural is very common.

So:

• en hodetelefon = one headphone / one earpiece
• hodetelefoner = headphones
• hodetelefonene = the headphones

In this sentence, the plural sounds natural.

It is a compound noun:

• plate
• samler
• -en

So:

• samler means collector
• plate in this compound refers to a record
• platesamler = record collector
• platesamleren = the record collector

Compound nouns are very common in Norwegian, and they are usually written as one word.

Bruker is the present tense of å bruke, which means to use.

So:

• å bruke = to use
• bruker = use / uses

Unlike English, Norwegian verbs do not change depending on the subject:

• jeg bruker = I use
• han bruker = he uses
• de bruker = they use

The verb form stays the same.

Its basic meaning is use.

In context, if someone is using headphones, that may naturally imply that they are wearing them, so English might sometimes translate it in a way that sounds like is wearing. But grammatically, bruker still means uses.

If you specifically want to emphasize wearing, Norwegian often uses har på seg.

So this sentence most directly means that the record collector is using the headphones.

Yes, this sentence has a very straightforward subject–verb–object order:

• Platesamleren = subject
• bruker = verb
• hodetelefonene = object

So it follows the same basic pattern as English:

The record collector uses the headphones.

Then the sentence would become more general or less specific.

For example:

• En platesamler bruker hodetelefoner.

That means a record collector uses headphones.

Compare:

• Platesamleren bruker hodetelefonene. = a specific record collector uses specific headphones
• En platesamler bruker hodetelefoner. = more general or indefinite

So the endings matter a lot for meaning.

No. Unlike German, Norwegian does not capitalize all nouns.

So:

• platesamleren
• hodetelefonene

are normally written with lowercase letters.

The first word here is capitalized only because it begins the sentence:

• Platesamleren bruker hodetelefonene.