Konduktøren siger, at vi skal vise vores billetter, før vi sætter os.

Because Danish usually puts the definite article at the end of the noun.

• en konduktør = a conductor
• konduktøren = the conductor

Here -en is the singular definite ending for a common-gender noun.

At introduces a subordinate clause, like English that in The conductor says that...

After verbs such as sige (say), tro (think), and vide (know), Danish often uses at to introduce what is being said, thought, or known.

So:

• Konduktøren siger = The conductor says
• at vi skal vise vores billetter = that we must show our tickets

After a modal verb like skal, Danish uses the bare infinitive, without at.

So you say:

• vi skal vise
• not vi skal at vise

This is similar to English must show or have to show, not must to show.

Here skal expresses obligation or instruction: something we are required to do.

That is why skal fits better than something like må. In modern Danish:

• skal often means must / have to / are supposed to
• må often means may / am allowed to

So vi skal vise vores billetter means this is a rule or requirement, not just permission.

Because possessives like min, din, vores, deres normally replace the article.

So Danish says:

• vores billetter = our tickets

not:

• de vores billetter

This works much like English: our tickets, not the our tickets.

Because vores refers to we/us, so the natural idea is that each person has a ticket, and Danish expresses that with the plural billetter.

Singular would be possible only if the group shared one ticket, which is not the normal situation.

Because at and før introduce subordinate clauses, and subordinate clauses do not use normal main-clause inversion.

So Danish keeps the subject before the finite verb:

• at vi skal vise...
• før vi sætter os

Compare that with a main clause, where Danish often follows the V2 rule. In subordinate clauses, the structure is usually calmer and more English-like.

Those commas mark the beginning of subordinate clauses.

So the sentence is divided like this:

• Konduktøren siger,
• at vi skal vise vores billetter,
• før vi sætter os.

You may also see Danish written without the comma before at or før, depending on comma style, but the version you have is very common and fully natural.

Sætte sig is a reflexive verb meaning to sit down or to seat oneself. It describes the action of moving into a seated position.

By contrast, sidde means to be sitting.

So:

• vi sætter os = we sit down
• vi sidder = we are sitting

Because the sentence talks about what happens before the action of sitting down, sætter os is the right choice.

Because sætte sig is a reflexive verb, and the reflexive pronoun comes with the verb.

In this sentence, the subject is vi, so the reflexive form is os:

• jeg sætter mig
• du sætter dig
• vi sætter os

So os is not an extra object in the English sense; it is part of the verb expression sætte sig.

Danish often uses the present tense in time clauses when the meaning is future.

So før vi sætter os is completely normal, even though the sitting happens after the ticket-showing.

English does something similar:

• before we sit down
• not usually before we will sit down

Yes, in many contexts inden and før can both work.

• før vi sætter os = before we sit down
• inden vi sætter os = before we sit down

In everyday usage, they are often very close in meaning. Inden can sometimes feel a little more formal or slightly more focused on before the point when, but in a sentence like this, either is natural.

That is a very common reaction. Danish spelling and pronunciation often do not match in a simple way.

Roughly:

• siger sounds like SEE-er
• sætter sounds roughly like SEH-dər or SEH-duh

A few helpful points:

• the g in siger is very weak and is not pronounced like English g
• the tt in sætter does not sound like a strong English t
• the final -er ending is usually a weak vowel sound

So yes: the written forms are longer and sharper-looking than the actual spoken forms.