Skapdøren lukkes sakte med dørdemperen.

Because Norwegian normally writes compound nouns as a single word.

• skap = cupboard, cabinet, closet, wardrobe (depending on context)
• dør = door

So:

• skapdør = cabinet door / cupboard door
• skapdøren = the cabinet door

English often uses separate words, but Norwegian usually combines them into one compound noun.

The ending -en is the definite article for many singular masculine nouns in Norwegian. Instead of putting the in front, Norwegian often adds the definiteness to the end of the noun.

So:

• en skapdør = a cabinet door
• skapdøren = the cabinet door

This is a very common feature of Norwegian.

Lukkes is the -s passive form of lukke.

• lukke = to close
• lukkes = is closed / closes

In this sentence, the most natural English meaning is something like:

• The cabinet door closes slowly
• or The cabinet door is closed slowly

In everyday usage here, it often sounds like the door closes on its own in that manner, especially because of the damper.

It is formally a passive form, but in sentences like this it can feel close to a middle meaning in English.

So Skapdøren lukkes sakte can suggest:

• the door is being closed slowly
• or the door closes slowly

Because the sentence mentions dørdemperen, the overall idea is usually that the door has a soft-closing mechanism, so it closes slowly as part of how it functions.

Sakte is an adverb meaning slowly, and it modifies the verb.

In a simple Norwegian main clause, an adverb like this often comes after the verb:

• Skapdøren lukkes sakte

That word order is very natural. English does the same thing here:

• The cabinet door closes slowly

Med usually means with, and here it shows the means or mechanism involved.

• med = with / by means of
• dørdemperen = the door damper / the soft-close mechanism

So med dørdemperen means something like:

• with the door damper
• by means of the door damper
• thanks to the soft-close mechanism

It does not mean that the door is somehow together with the damper in a literal social sense. It means the damper is the device that makes the slow closing happen.

For the same basic reason as skapdøren: Norwegian often uses the definite form when the thing is specific and identifiable from the context.

• en dørdemper = a door damper
• dørdemperen = the door damper

Here it likely refers to the particular damper attached to that door, so the definite form is natural.

It is another compound noun.

• dør = door
• demper = damper, muffler, shock absorber, soft-closing device, something that dampens movement
• dørdemper = door damper / soft-close damper
• dørdemperen = the door damper

This is another good example of how Norwegian builds longer nouns by combining smaller ones.

Not always. Skap is a broad word and can mean different things depending on context, such as:

• cabinet
• cupboard
• closet
• wardrobe

So skapdøren could be:

• the cabinet door
• the cupboard door
• the wardrobe door

The exact English choice depends on what kind of skap is being talked about.

Yes. Because of lukkes, the sentence can be rendered a few different ways in English, depending on context.

Possible translations include:

• The cabinet door closes slowly with the door damper.
• The cabinet door is closed slowly by the door damper.
• The cabinet door closes slowly thanks to the soft-close mechanism.

In many real-life situations, the last version may sound most natural in English, because it captures the idea of a soft-closing device.

A more active-style version could be something like:

• Dørdemperen lukker skapdøren sakte.

That literally means The door damper closes the cabinet door slowly.

However, Norwegian often prefers the original wording because it focuses on what happens to the door, not on treating the damper as a very active agent. So Skapdøren lukkes sakte med dørdemperen sounds quite natural when describing how the door functions.

Yes. Lukkes is present tense.

So the sentence describes something that happens generally or regularly:

• the cabinet door closes slowly
• the cabinet door is closed slowly

It is not specifically past tense or future tense. It sounds like a general description of how the door works.