Politiet kan sprenge døren.

Because politiet is the definite form of politi.

• politi = police / a police force in a general sense
• politiet = the police

In Norwegian, definiteness is often shown by adding an ending to the noun instead of using a separate word like the.

So:

• politi = police
• politiet = the police

In this sentence, politiet means the police as an institution or group.

Grammatically, it behaves like a singular noun in Norwegian, even though in English the police is treated as plural.

So Norwegian says:

• Politiet kan ...

not something plural like Politiene kan ... in this context.

A useful way to think of it is that Norwegian treats politiet more like the police force or the police department.

Kan is the present tense of kunne, which usually means can, be able to, or sometimes may depending on context.

So Politiet kan sprenge døren can mean things like:

• The police can blow up the door
• The police are able to blow up the door
• The police may blow up the door

The exact meaning depends on context. On its own, kan can express either:

• ability
• possibility
• permission in some situations

Because after a modal verb like kan, Norwegian uses the bare infinitive.

So:

• kan sprenge = can blow up
• not kan sprenger

This is similar to English:

• can blow up
• not can blows up

Other common modal verbs that work the same way are:

• skal
• vil
• må
• bør

For example:

• Politiet må sprenge døren. = The police must blow up the door.

Sprenge usually means to blow up, to blast, or to break open using explosives or force.

In this sentence, it most naturally suggests forcing the door open by explosive means or a powerful breach.

Depending on context, English translations might include:

• blow up
• blast open
• breach

So this is a fairly strong and dramatic verb, not just ordinary opening.

Because døren is the definite form of dør, meaning the door.

Here is the pattern:

• en dør = a door
• døren = the door

Again, Norwegian usually adds definiteness to the end of the noun.

So:

• sprenge en dør = blow up a door
• sprenge døren = blow up the door

Because Norwegian normally expresses the by attaching an ending to the noun.

So instead of saying something like the door, Norwegian usually says:

• dør
  • definite ending = døren

This is one of the biggest differences from English.

Compare:

• en bil = a car

• bilen = the car

• en dør = a door
• døren = the door

The word order is:

Subject + verb + infinitive + object

So:

• Politiet = subject
• kan = finite verb
• sprenge = infinitive
• døren = object

That gives:

Politiet kan sprenge døren.

This is a normal Norwegian main-clause word order.

Yes. Kan can sometimes be understood as may or might be able to, not only can.

Without more context, the sentence can be interpreted in more than one way:

• ability: the police are able to do it
• possibility: it is possible that they will do it
• permission/authority: they are allowed to do it

If the surrounding context is legal or tactical, English might translate it as may rather than can.

Both are possible in Bokmål.

• døren
• døra

Both mean the door.

The difference is mostly one of style and form preference:

• døren is often seen as more traditional or conservative Bokmål
• døra is also very common and often sounds more everyday or informal

So Politiet kan sprenge døren and Politiet kan sprenge døra are both acceptable in Bokmål.

In a yes/no question, Norwegian usually puts the finite verb first:

• Kan politiet sprenge døren?

This means:

• Can the police blow up the door?

So the statement:

• Politiet kan sprenge døren.

becomes the question:

• Kan politiet sprenge døren?

Døren is roughly pronounced like DUR-en, but with a vowel that does not exist in standard English.

A few points:

• ø is a rounded front vowel
• your lips should be rounded, somewhat like for oo, but your tongue should be positioned more like for eh or i

A rough learner-friendly approximation is:

• DUR-en or DER-en with rounded lips

The r is also pronounced before the ending, and the final -en is the definite ending.

Yes, depending on what exactly is meant.

For example:

• å åpne døren = to open the door
• å bryte opp døren = to break open the door
• å slå inn døren = to smash in the door
• å sprenge døren = to blow up / blast open the door

So sprenge is specifically a forceful, explosive kind of opening, not just normal opening.