De roltrap is kapot, dus we moeten lopen.

Because roltrap is a de-word in Dutch. Nouns in Dutch take either de or het, and this usually has to be learned word by word.

• de roltrap = the escalator

There is no simple rule that lets you reliably guess all noun genders, so learners usually memorize the article together with the noun:

• de roltrap
• de trap = the stairs / staircase
• het station = the station

Literally, roltrap is made up of:

• rollen / rol- = to roll / rolling
• trap = stairs

So roltrap is basically rolling stairs, which is a very transparent Dutch word for escalator.

Because kapot is being used after the verb is, as a predicate adjective.

In Dutch:

• before a noun, adjectives usually take -e
• after zijn, they usually do not take -e

Compare:

• de kapotte roltrap = the broken escalator
• de roltrap is kapot = the escalator is broken

So in your sentence, kapot is correct because it comes after is.

Here, kapot means broken, not working, or out of order.

So:

• De roltrap is kapot = The escalator is broken / not working.

Dutch speakers use kapot very often in everyday speech for things that do not function properly:

• Mijn fiets is kapot. = My bike is broken.
• De lift is kapot. = The elevator is out of order.

Yes. stuk can often mean the same thing as kapot in this kind of sentence.

• De roltrap is kapot.
• De roltrap is stuk.

Both can mean The escalator is broken.

A small nuance:

• kapot often feels a bit more everyday and general
• stuk is also very common, especially for something not functioning

In many situations, they are interchangeable.

Because dus is usually a coordinating conjunction in Dutch, similar to so in English. It does not normally force inversion.

So the normal word order stays:

• dus we moeten lopen = so we have to walk

Compare that with words like daarom or dus used more adverbially in some styles, where inversion can happen:

• Daarom moeten we lopen.

But in your sentence, dus we moeten lopen is completely natural and straightforward.

Yes, but the structure changes.

• De roltrap is kapot, dus we moeten lopen.
• De roltrap is kapot. Daarom moeten we lopen.

With daarom, inversion is normal:

• Daarom moeten we lopen.
  • literally: Therefore must we walk

So:

• dus often links two clauses more like English so
• daarom means therefore / that’s why, and usually triggers inversion

Both are correct, but dus feels especially natural in everyday spoken Dutch here.

Because moeten is a modal verb, and modal verbs are followed by the bare infinitive in Dutch.

So:

• we moeten lopen = we must / have to walk

Not:

• we moeten te lopen ❌

This is similar to English:

• we must walk not
• we must to walk

Other Dutch modal verbs work the same way:

• Ik kan zwemmen. = I can swim.
• Zij wil gaan. = She wants to go.
• Wij mogen blijven. = We may stay.

Here, lopen means to walk or to go on foot.

In this context, because the escalator is broken, the intended meaning is basically:

• we have to walk
  or
• we have to take the stairs on foot

Dutch often uses lopen in a broader, very natural way where English might choose different verbs depending on context.

Moeten means must or have to. It expresses necessity or obligation.

So:

• we moeten lopen = we must walk / we have to walk

In this sentence, the idea is practical necessity:

• the escalator is broken
• therefore walking is necessary

It does not necessarily sound as strong as an order; it can simply describe the situation.

A rough pronunciation guide for an English speaker is:

• de → duh
• roltrap → ROL-trahp
• is → iss
• kapot → kah-POT
• dus → duss
• we → vuh
• moeten → MOO-tuhn
• lopen → LOH-puhn

A few helpful notes:

• Dutch r can vary a lot by region.
• oe in moeten sounds like oo in food.
• o in lopen is a long oh sound.
• eu is not in this sentence, which is nice, because that is a harder Dutch vowel for English speakers.

No, not usually.

Dutch we is usually pronounced more like vuh or a very weak wuh, not like the English word wee.

So:

• we moeten lopen

sounds closer to:

• vuh MOO-tuhn LOH-puhn

This weak pronunciation is very common in normal speech.

No. In standard modern Dutch:

• lopen = to walk
• rennen / hardlopen = to run

So in your sentence, lopen definitely means walk, not run.

Dutch main clauses usually follow the V2 rule, which means the finite verb goes in the second position.

In:

• De roltrap is kapot

the first element is:

• De roltrap

and the finite verb is:

• is

So the structure is normal Dutch main-clause word order.

The same happens in the second clause:

• we moeten lopen
  • first element: we
  • finite verb: moeten
  • infinitive at the end: lopen

Yes, very natural. It is a simple, idiomatic everyday sentence.

A Dutch speaker could easily say:

• De roltrap is kapot, dus we moeten lopen.

It sounds normal in places like train stations, shopping centers, airports, or metro stations.