Luftboblen er i leiren.

Because Norwegian usually puts the definite article at the end of the noun instead of using a separate word before it.

So:

• luftboblen = the air bubble
• leiren = the ... from the meaning you were shown

This is one of the biggest differences from English. In many basic Norwegian sentences, the is a suffix, not a separate word.

Yes. Norwegian normally writes compound nouns as one word.

So luftboble is built from:

• luft = air
• boble = bubble

Together, they make luftboble = air bubble.

This is very common in Norwegian. Where English may use two words, Norwegian often uses one compound word.

It shows that the noun is definite singular.

The basic form is en/ei luftboble.
The definite form is luftboblen, meaning the air bubble.

A useful pattern is:

• nouns ending in unstressed -e often form the definite singular by adding -n
• so luftboble → luftboblen

In writing, that looks like -en, but it is really the word ending in -e plus -n.

It is also a definite singular noun.

So whatever noun your translation gave you, leiren means the ... in that sentence.

The exact dictionary form depends on the meaning already shown to you, but grammatically the important point is that leiren is a definite form, not an indefinite one.

Er is the present tense of å være, which means to be.

So here it means is.

A very useful thing to know is that Norwegian verbs do not change for person the way English verbs do. So you get:

• jeg er = I am
• du er = you are
• han/hun er = he/she is
• de er = they are

The form stays er.

I usually means in.

It is used when something is located inside something, or within an area, place, or substance.

So er i leiren means that the air bubble is located in that place or material.

As always with prepositions, English and Norwegian do not match perfectly in every context, so it is best to learn i as part of whole phrases too.

It is the normal, neutral word order for a Norwegian main clause:

• Luftboblen = subject
• er = finite verb
• i leiren = prepositional phrase showing location

So the pattern is:

subject + verb + place

That is very common in simple statements.

Yes. Norwegian main clauses follow the V2 rule, which means the finite verb normally comes in the second position.

In this sentence, the subject comes first, so the verb naturally comes right after it:

Luftboblen er i leiren

If you move another part to the front, the verb still stays second:

I leiren er luftboblen

That version is possible, but it gives more emphasis to the location.

Yes, that is grammatically possible.

It means the same basic thing, but it sounds more marked or emphatic, because it highlights i leiren first.

Compare:

• Luftboblen er i leiren = neutral statement
• I leiren er luftboblen = more emphasis on where it is

Because of the V2 rule, once I leiren is moved to the front, er must still come second.

Not as a normal complete sentence.

In ordinary Norwegian statements, you need a finite verb, and here that verb is er.

So:

• Luftboblen er i leiren = complete sentence
• Luftboblen i leiren = not a normal full sentence by itself

Without er, it would sound incomplete unless it were part of a heading, note, or fragment.