Røret ligger under gulvet.

Because rør is a neuter noun in Norwegian, and -et is the usual ending for the definite singular form.

• et rør = a pipe / a tube
• røret = the pipe / the tube

So Røret ligger under gulvet starts with the pipe as the subject.

Rør can mean pipe or tube, depending on context. In a sentence like this, many learners will understand it as pipe, especially because something being under a floor often suggests plumbing, heating, or construction.

So the meaning depends on the situation:

• et rør = a pipe
• et rør = a tube

Norwegian often uses the same word where English makes a more specific distinction.

In Norwegian, ligge is often used to describe where something is physically located, especially when it is resting in a place.

So:

• Røret ligger under gulvet = the pipe is located under the floor

If you used er, the sentence would still be understandable, but ligger sounds more natural when talking about physical position. Norwegian uses several verbs like this:

• ligge = lie, be situated
• stå = stand, be standing
• sitte = sit, be seated / be positioned
• henge = hang

This is more common in Norwegian than in English, where is is often enough.

Ligger is the present tense of ligge.

Basic forms:

• å ligge = to lie / to be located
• ligger = lies / is lying / is located

So Røret ligger under gulvet is in the present tense: The pipe lies / is under the floor.

For the same reason as røret: gulv is also a neuter noun, and here it is in the definite singular form.

• et gulv = a floor
• gulvet = the floor

After under, Norwegian often uses the definite form when talking about a specific floor:

• under gulvet = under the floor

So the sentence means the pipe is under the floor, not just under a floor in general.

No. Norwegian does not have the kind of case system that would force a special noun form after most prepositions.

So under is simply followed by the normal noun form:

• under gulvet = under the floor
• under et gulv = under a floor

You do not need to learn different case endings here the way you might in German, for example.

Yes. The basic order here is:

• Røret = subject
• ligger = verb
• under gulvet = place expression

But Norwegian also allows fronting for emphasis or style:

• Under gulvet ligger røret.

That still means the same thing, but now under gulvet is emphasized first. Because Norwegian is a V2 language, the verb still stays in second position:

• Under gulvet
  • ligger
    • røret

A useful approximate pronunciation is:

• rør: something like rur but with rounded lips and a vowel English does not really have
• røret: roughly RUR-uh or RØR-uh, depending on how carefully you want to represent the vowel

Key points:

• ø is a front rounded vowel; English does not have an exact match
• the final -et is often pronounced like a weak -e sound in many varieties of Norwegian speech

The most important sound for learners here is ø.

A rough guide is:

• gulv: like goolv but shorter
• gulvet: roughly GOOL-veh or GOOL-vuh

Points to notice:

• u in Norwegian is not exactly the same as English oo, but that approximation is often good enough at first
• the -et ending is usually weak in everyday speech

Yes, that is the closest literal translation.

But in natural English, people often prefer:

• The pipe is under the floor
• The pipe is located under the floor

So the Norwegian sentence uses ligger, while natural English often just uses is.

In this sentence it is clearly physical location: something is literally below the floor.

In general, under can also be used in more abstract ways in Norwegian, just like English:

• under press = under pressure
• under arbeid = under construction / being worked on

But here, with røret and gulvet, the meaning is straightforwardly physical.

Because Norwegian usually puts the definite meaning on the end of the noun instead of using a separate article like English the.

So:

• røret = the pipe
• gulvet = the floor

That is one of the biggest structural differences from English. In this sentence, both nouns are definite, but neither needs a separate word like the.