Bowlingkulen ruller over siktemerket.

Because Norwegian usually writes compound nouns as one word.

• bowlingkule = bowling
  • kule
• siktemerke = sikte
  • merke

This is very common in Norwegian. Where English often uses two words, Norwegian often prefers a compound:

• bowling ball → bowlingkule
• target mark / aiming mark → siktemerke

So seeing long nouns is completely normal.

In Norwegian, the definite article is usually attached to the end of the noun.

So instead of saying a separate word like English the, Norwegian often does this:

• en bowlingkule = a bowling ball
• bowlingkulen = the bowling ball

and

• et siktemerke = an aiming mark
• siktemerket = the aiming mark

So the sentence does contain the, just as endings:

• -en in bowlingkulen
• -et in siktemerket

Because the nouns have different grammatical genders.

• en bowlingkule → definite bowlingkulen
• et siktemerke → definite siktemerket

In Bokmål, the usual definite endings are:

• -en for many common gender / masculine-style nouns
• -et for neuter nouns

So the different endings are not random; they show the noun’s gender.

Ruller is the present tense of å rulle.

• å rulle = to roll
• ruller = rolls / is rolling

Norwegian verbs do not change according to person the way English does. So the same present-tense form is used with all subjects:

• jeg ruller
• du ruller
• den ruller
• vi ruller

That makes Norwegian verb conjugation simpler than English in this area.

In this sentence, over most naturally means something like across or over and past the aiming mark.

Since a bowling ball rolls on the lane, over siktemerket does not suggest that the ball is flying in the air above it. It means the ball rolls across that mark on the lane.

So in context, over is best understood as movement crossing that point.

It is a compound noun:

• sikte = aim / line up / sight
• merke = mark / marker

So siktemerke literally means something like aiming mark or target marker.

With the definite ending:

• siktemerket = the aiming mark

This is a good example of how Norwegian often builds precise meanings through compounds.

This is the normal word order for a simple statement:

• Subject: Bowlingkulen
• Verb: ruller
• Adverbial / prepositional phrase: over siktemerket

So it follows a basic pattern like:

The bowling ball + rolls + over the aiming mark

More generally, Norwegian is a V2 language, which means the finite verb usually comes in the second position in main clauses. In this sentence, the subject comes first, so the verb naturally comes next.

It is a loanword from English, but it is fully usable in Norwegian.

Norwegian often borrows words, especially for sports, technology, and popular culture. Once borrowed, they behave like Norwegian words in grammar.

So:

• bowling is borrowed
• kule is Norwegian
• together they form bowlingkule
• and the definite form becomes bowlingkulen

So even though part of the word comes from English, the whole noun follows Norwegian rules.

Yes, in Bokmål that can also be possible, depending on whether you use the feminine form of kule.

The noun kule can be treated as:

• common gender / masculine-style: en kule → kulen
• feminine: ei kule → kula

So both of these can occur:

• bowlingkulen
• bowlingkula

The sentence you were given uses bowlingkulen, which is perfectly normal Bokmål. A learner should mainly recognize that both patterns may exist for some nouns.

It would be:

En bowlingkule ruller over et siktemerke.

That means a bowling ball rolls over an aiming mark.

Compare:

• en bowlingkule → bowlingkulen
• et siktemerke → siktemerket

This is a useful pair to memorize, because it shows both the indefinite articles and the definite endings.