Sylinderfallen og sperrefallen sitter i låskassen.

Because they are in the definite singular form: the cylinder latch, the dead latch/blocking latch, the lock case.

In Norwegian, definiteness is often added to the end of the noun instead of using a separate word like the.

• en sylinderfalle = a cylinder latch

• sylinderfallen = the cylinder latch

• en sperrefalle = a blocking latch / dead latch

• sperrefallen = the blocking latch

• en låskasse = a lock case
• låskassen = the lock case

So the -en ending here works like English the.

In Norwegian, a noun often shows definiteness by taking an ending, rather than needing a separate article.

So instead of saying something like the lock case with a separate the, Norwegian usually says:

• låskassen = the lock case

This is one of the biggest differences from English. English uses a separate word; Norwegian often attaches the meaning directly to the noun.

Because Norwegian verbs do not change form for singular and plural subjects in the present tense.

So:

• Den sitter = It sits / is located
• De sitter = They sit / are located

The verb stays sitter either way.

That is different from English, where we say:

• it sits
• they sit

In Norwegian, both use sitter.

Norwegian often prefers a position/location verb where English might simply use is.

Here, sitter suggests that the parts are positioned/fitted/located in the lock case. It does not necessarily mean they are literally “sitting” like a person. In technical or physical descriptions, Norwegian often uses verbs like:

• stå = stand
• ligge = lie
• sitte = sit / be fixed / be positioned

So sitter i låskassen means something like:

• are situated in the lock case
• are fitted in the lock case

Using er would sound less natural here.

Sitter i often means is in, is mounted in, is fitted in, or is located in, depending on context.

In this sentence, it means the two parts are physically located inside the lock case.

So sitter i låskassen is not mainly about posture; it is about placement or installation.

It is a prepositional phrase:

• i = in
• låskassen = the lock case

Together: in the lock case

This phrase tells you where the latches are located.

Yes. Norwegian uses compound nouns very heavily.

They can be broken down like this:

• sylinder + falle = sylinderfalle
• sperre + falle = sperrefalle
• lås + kasse = låskasse

This is very normal in Norwegian. English sometimes writes similar ideas as two words, hyphenated words, or fixed technical terms, but Norwegian often combines them into one word.

For learners, it helps to look for the smaller parts inside a long noun.

Because the compound noun is based on sperrefalle, where sperre- functions as the first part of the compound.

Then the definite ending is added:

• en sperrefalle
• sperrefallen

This is a normal pattern in Norwegian compound nouns: first build the compound, then add the definite ending to the whole word.

Yes. It is standard Norwegian main-clause word order:

• Sylinderfallen og sperrefallen = subject
• sitter = verb
• i låskassen = place/location phrase

So the structure is basically:

Subject + Verb + Adverbial

That is very similar to normal English word order here.

Not naturally in this context.

Without the definite endings, the nouns would sound indefinite or dictionary-like, and the sentence would usually feel wrong in ordinary prose. If you are talking about specific parts in a specific lock, Norwegian normally uses the definite forms:

• sylinderfallen
• sperrefallen
• låskassen

That matches the idea of specific, known parts.

Yes, in this sentence it does.

• sylinderfallen og sperrefallen = the cylinder latch and the blocking latch

It simply joins the two nouns into one compound subject.

In compound nouns, the first part usually gets the main stress.

So you would typically hear stress roughly like this:

• SYlinderfallen
• SPERrefallen
• LÅSkassen

That first-part stress is very common in Norwegian compounds and can help you recognize them when listening.

This is Bokmål.

A clear clue is sitter i låskassen and the definite forms ending in -en. The sentence looks fully normal in Bokmål technical language.

They are treated here as common gender nouns in Bokmål, which take:

• indefinite article en
• definite ending -en

So:

• en sylinderfalle → sylinderfallen
• en sperrefalle → sperrefallen
• en låskasse → låskassen

For an English speaker, the main practical point is to learn the article together with the noun, because the article affects the definite form.