Urverket sitter i automatklokken.

Because urverket is the definite form of et urverk.

• et urverk = a watch movement / the inner mechanism
• urverket = the watch movement

In Norwegian, nouns usually add an ending to show the:

• et urverk → urverket
• en/ei klokke → klokken

So this sentence is talking about a specific movement, not just any movement.

For the same reason: automatklokken is the definite form.

• en automatklokke = an automatic watch
• automatklokken = the automatic watch

The sentence refers to a particular watch, so the definite form is used.

It is a compound noun:

• automat = automatic
• klokke = watch / clock

So automatklokke means automatic watch.

Very often, Norwegian combines words into one noun where English might also use a compound or adjective + noun structure.

This is a very common Norwegian pattern. Norwegian often uses position verbs where English would simply use is.

Here, sitter literally means sits, but in many contexts it really means something like:

• is situated
• is fitted
• is placed
• is sitting inside

So Urverket sitter i automatklokken suggests that the movement is sitting/fitted inside the automatic watch.

Using er would be more neutral and less physical. Sitter gives a sense of how the movement is positioned in the watch.

Yes, you probably can, and it would be understood. But it sounds less natural in many situations.

• er i = simply is in
• sitter i = is sitting/fitted in, with a stronger sense of physical placement

Norwegian often prefers sitte, stå, or ligge when describing where something is located.

So sitter i is the more idiomatic choice here.

I means in / inside.

Since the movement is located inside the watch, i is the natural preposition.

• i klokken = in the watch
• på klokken would mean on the watch, which would be wrong here

So sitter i automatklokken = is fitted inside the automatic watch.

The sentence follows normal Norwegian main-clause word order:

• Urverket = subject
• sitter = verb
• i automatklokken = prepositional phrase

So the structure is:

Subject + Verb + Place

That is very similar to basic English word order: The movement + sits/is + in the automatic watch

Because the sentence is talking about specific, identifiable things:

• urverket = the movement
• automatklokken = the automatic watch

This often happens when the speaker and listener both know which objects are meant, or when the context makes them clear.

Using definite forms in both places is completely normal in Norwegian.

• urverk is neuter: et urverk
• automatklokke is usually common gender: en automatklokke
  (Since klokke is often feminine in Norwegian, you may also see feminine forms in some varieties: ei klokke, klokka.)

In this sentence, the forms are:

• et urverk → urverket
• en automatklokke → automatklokken

Not exactly.

Automatklokke is the normal compound noun for an automatic watch. It refers to a specific type of watch.

Automatisk klokke would sound more like an automatic clock/watch in a more descriptive or literal way, and it is not the usual term here.

So in this context, automatklokke is the natural word.

No. That is one of the big things English speakers have to get used to in Norwegian.

Sitte can be used for:

• people: Han sitter på stolen = He is sitting on the chair
• objects: Bildet sitter på veggen = The picture is attached/on the wall
• parts inside something: Batteriet sitter i fjernkontrollen = The battery is in the remote
• things that fit tightly: Skruen sitter fast = The screw is stuck

So here, sitter does not mean the movement is literally sitting like a person. It means it is positioned/fitted inside the watch.

A natural indefinite version would be:

Et urverk sitter i en automatklokke.

That means:

• et urverk = a movement
• en automatklokke = an automatic watch

This sounds more general, as if you are talking about any movement and any automatic watch, rather than a specific one.