Hun bor i tredje etasje.

Hun means she when it is the subject of the sentence.

In this sentence, Hun bor i tredje etasje, hun is the person doing the action, so she is the correct meaning.

A useful contrast:

• hun = she (subject)
• henne = her (object)

So:

• Hun bor i tredje etasje = She lives on the third floor.
• Jeg kjenner henne = I know her.

Bor is the present tense of å bo, which means to live or to reside somewhere.

So:

• å bo = to live somewhere
• bor = lives / am living / are living, depending on the subject

Examples:

• Jeg bor i Oslo = I live in Oslo.
• De bor sammen = They live together.

In this sentence, Hun bor i tredje etasje means she resides there, not just that she happens to be there at the moment.

This is an important difference.

• Hun bor i tredje etasje = She lives on the third floor.
  This describes where she resides permanently or normally.

• Hun er i tredje etasje = She is on the third floor.
  This describes where she is right now.

So bor is about residence, while er is about current location.

Because prepositions do not match perfectly between languages.

In standard Norwegian, the natural expression is i tredje etasje, even though English uses on:

• English: on the third floor
• Norwegian: i tredje etasje

So you should learn this as a fixed, natural pattern:

• bo i første etasje
• bo i andre etasje
• bo i tredje etasje

Even if English uses on, Norwegian normally uses i here.

Tredje means third.

It is an ordinal number, meaning a number used for position in a sequence:

• første = first
• andre = second
• tredje = third
• fjerde = fourth

So tredje etasje means third floor.

This is different from cardinal numbers like:

• tre = three

So:

• tre etasjer = three floors
• tredje etasje = third floor

In Norwegian, when talking about what floor someone lives on, it is very common to use the simpler expression:

• i tredje etasje

This works like an idiomatic location phrase.

You can also say i den tredje etasjen, but that sounds more specific, heavier, or more formal, as if you are referring to a particular floor in a more explicit way.

For everyday speech, i tredje etasje is the normal choice.

Etasje is the indefinite form: floor Etasjen is the definite form: the floor

In the expression i tredje etasje, Norwegian normally uses the noun without the definite ending. This is just how this kind of floor-expression is usually built.

Compare:

• Hun bor i tredje etasje = She lives on the third floor.
• Etasjen er nyoppusset = The floor has been renovated.

So even though English says the third floor, Norwegian often does not use the definite form in this construction.

Yes. It follows normal main-clause word order:

• Hun = subject
• bor = verb
• i tredje etasje = location phrase

So the structure is:

Subject + Verb + Place

This is very standard:

• Jeg bor i Bergen
• Han jobber på sykehus
• Hun bor i tredje etasje

Also remember that Norwegian main clauses usually follow the verb-second rule. If you move the location phrase to the front, the verb still stays in second position:

• I tredje etasje bor hun

That is correct, but less neutral than the original sentence.

A rough pronunciation guide for an English speaker is:

Hoon bor ee TRER-yeh eh-TAH-shuh

A few notes:

• Hun has a vowel that is not exactly like English oo, but hoon is a rough approximation.
• bor sounds somewhat like boor.
• tredje can be tricky; the middle consonants are compressed in natural speech.
• etasje is pronounced roughly eh-TAH-shuh.

Pronunciation varies a bit by region, but this should help you recognize the sentence.

Yes. This pattern is very productive.

Examples:

• Hun bor i første etasje = She lives on the first floor.
• Han bor i andre etasje = He lives on the second floor.
• De bor i fjerde etasje = They live on the fourth floor.

So once you know the pattern bo i + ordinal number + etasje, you can use it for many similar sentences.