Det er svært at være tålmodig, når bussen er forsinket.

In Det er svært at ..., det is a dummy subject or formal subject. Danish often uses det in general statements like this, just as English uses it in It is hard to...

So:

• Det er svært = It is difficult
• at være tålmodig = to be patient

A more literal structure is:

• It is difficult to be patient

The real idea comes in the infinitive phrase at være tålmodig.

Because svært is the neuter singular form of the adjective svær.

After det er, Danish usually uses the neuter form of the adjective:

• Det er godt = It is good
• Det er svært = It is difficult
• Det er vigtigt = It is important

So in this sentence, det triggers the form svært.

Here, at is the infinitive marker, like English to.

• at være = to be

So:

• Det er svært at være tålmodig = It is hard to be patient

This is a very common Danish pattern:

• Det er nemt at lære = It is easy to learn
• Det er rart at komme hjem = It is nice to come home

Because tålmodig describes the person who is being patient, not the dummy subject det.

In other words, the sentence means:

• It is difficult for someone to be patient

That implied someone is a person, so Danish uses tålmodig, not neuter tålmodigt.

Compare:

• Han er tålmodig = He is patient
• Hun er tålmodig = She is patient

In this sentence, the person is not named, but the adjective still refers to a person.

Når means when in the sense of a general situation or something that happens repeatedly or typically.

So here it means:

• when the bus is delayed

It is not necessarily talking about one single specific future event. It sounds like a general truth: being patient is hard whenever the bus is delayed.

A useful contrast is:

• når = when, whenever, in general
• da = when, at a specific time in the past

Example:

• Når bussen er forsinket, bliver folk irriterede. = When the bus is delayed, people get annoyed.
• Da bussen var forsinket i går, kom jeg for sent. = When the bus was delayed yesterday, I arrived late.

Bussen means the bus. The ending -en is the Danish way of making many common-gender nouns definite.

So:

• en bus = a bus
• bussen = the bus

Danish often adds the definite article as an ending instead of using a separate word like English the.

In this sentence, forsinket functions like an adjective meaning delayed.

• Bussen er forsinket = The bus is delayed

It comes from the verb at forsinke = to delay, but here it behaves as a description of the bus’s state.

You can think of it as similar to English:

• The bus is delayed
• The door is closed
• The shop is open

These can feel verbal in origin, but in sentences like this they often work adjectivally.

Because in this subordinate clause, Danish keeps the normal subject-verb order:

• bussen = subject
• er = verb
• forsinket = complement

So:

• når bussen er forsinket = when the bus is delayed

This is different from main clauses, where Danish often has verb-second word order.

Compare:

• Bussen er forsinket. = The bus is delayed.
• Nu er bussen forsinket. = Now the bus is delayed.

But after a subordinating conjunction like når, the clause stays in subordinate-clause order.

No, that would sound wrong here.

Tålmodigt is the neuter form, but the sentence is about a person being patient, not about det being patient. Since the understood subject is human, Danish uses:

• at være tålmodig

So the correct sentence is:

• Det er svært at være tålmodig, når bussen er forsinket.

Yes, svært is very natural here. It means difficult/hard.

You could also use vanskeligt, which is a bit more formal or bookish in many contexts:

• Det er vanskeligt at være tålmodig...

But svært is the more common everyday choice.

Yes. The subordinate clause can come first:

• Når bussen er forsinket, er det svært at være tålmodig.

This means the same thing, but now the when-clause is emphasized first.

Notice the word order in the main clause after the fronted subordinate clause:

• ..., er det svært ...

That is normal Danish verb-second word order in the main clause.

You could make the subject explicit:

• Han har svært ved at være tålmodig, når bussen er forsinket. = He has difficulty being patient when the bus is delayed.
• Hun synes, det er svært at være tålmodig, når bussen er forsinket. = She thinks it is hard to be patient when the bus is delayed.

The original sentence is more general and impersonal, like a general observation.

A close breakdown is:

• Det = it
• er = is
• svært = difficult
• at være = to be
• tålmodig = patient
• når = when
• bussen = the bus
• er = is
• forsinket = delayed

So the full structure is:

• It is difficult to be patient when the bus is delayed.