Jeg prøver at finde ud af, hvorfor bussen er forsinket.

Because prøver is the present tense form of the verb at prøve.

• at prøve = to try
• jeg prøver = I try / I am trying

In Danish, present tense verbs often end in -r:

• jeg finder = I find
• jeg tænker = I think
• jeg prøver = I try

So prøve is the infinitive, while prøver is the form that matches jeg in a normal present-tense sentence.

At finde ud af is a fixed expression meaning to find out or to figure out.

It works a lot like an English phrasal verb:

• finde = find
• ud af helps create the meaning find out

So:

• jeg prøver at finde ud af = I’m trying to find out

You usually need the whole expression. If you say only finde, it often just means find in the physical sense, like locating something.

Examples:

• Jeg finder min taske. = I find my bag.
• Jeg finder ud af det. = I find out / I figure it out.

Because Danish normally uses at before an infinitive, just like English uses to.

• at finde = to find
• at prøve = to try
• at spise = to eat

So in this sentence:

• Jeg prøver at finde ud af ...
• literally: I try to find out ...

This is very natural Danish structure:
verb + at + infinitive

Because there are two verbs doing two different jobs:

1. prøver = the main finite verb in the sentence
2. finde = an infinitive that depends on prøver

So the structure is:

• Jeg prøver = I am trying
• at finde ud af = to find out

Put together:

• Jeg prøver at finde ud af ... = I’m trying to find out ...

This is similar to English:

• I want to go
• I need to know
• I’m trying to find out

This is a very common question, because Danish word order changes in subordinate clauses.

Here, hvorfor bussen er forsinket is not a direct question. It is an embedded question, also called an indirect question.

Compare:

• Direct question: Hvorfor er bussen forsinket? = Why is the bus delayed?
• Embedded question: Jeg prøver at finde ud af, hvorfor bussen er forsinket. = I’m trying to find out why the bus is delayed.

In embedded questions, Danish usually uses normal clause order:

• subject + verb
• bussen er

So:

• hvorfor er bussen forsinket? = direct question
• hvorfor bussen er forsinket = embedded question

Because bussen means the bus, while en bus means a bus.

Danish often puts the definite article at the end of the noun:

• en bus = a bus
• bussen = the bus

This ending -en is the definite article for many common nouns.

More examples:

• en bil = a car
• bilen = the car
• en bog = a book
• bogen = the book

So bussen is exactly what you would expect if the sentence means the bus.

Er forsinket means is delayed.

• er = is / are
• forsinket = delayed

So:

• Bussen er forsinket. = The bus is delayed.

Here forsinket is functioning like an adjective after er, just like in English:

• The bus is late
• The bus is delayed

Danish often uses være + adjective/past participle in this kind of structure.

Both can relate to lateness, but they are not always used in exactly the same way.

• sen = late
• forsinket = delayed

For transport, forsinket is especially common:

• Bussen er forsinket. = The bus is delayed.

You could also hear:

• Bussen er sen. = The bus is late.

But forsinket often sounds a bit more specific, especially for buses, trains, flights, and schedules.

For people, sen is often more natural:

• Jeg kommer for sent. = I’m arriving late.

Yes. Danish present tense often covers both the simple present and the English be + -ing form.

So:

• Jeg prøver can mean I try
• but in this context it very naturally means I’m trying

Danish usually does not need a separate progressive form like English does.

More examples:

• Jeg læser. = I read / I am reading
• Hun arbejder. = She works / She is working

The context tells you which English translation sounds best.

Yes, absolutely.

• Jeg prøver at finde ud af ...
• Jeg forsøger at finde ud af ...

Both mean I’m trying to find out ...

The difference is mostly style:

• prøver is very common and everyday
• forsøger can sound a little more formal or slightly more deliberate

In ordinary conversation, prøver is often the most natural choice.

Yes, Danish particles can sometimes move depending on the structure, but learners should first memorize finde ud af as one unit.

For example:

• Jeg prøver at finde ud af det. = I’m trying to figure it out.
• Jeg finder det ud. is possible in some structures with finde ud, but with finde ud af plus a clause, the full expression matters.

In your sentence, the pattern is:

• finde ud af, hvorfor ...

So it is best to learn:

• finde ud af noget
• finde ud af, om ...
• finde ud af, hvorfor ...
• finde ud af, hvad ...

Treat it like a chunk at first.

A rough pronunciation guide is:

• jeg ≈ yai or very soft yai/yei depending on accent
• prøver ≈ PROE-ver, with ø being a rounded vowel that English does not really have
• bussen ≈ BOO-sen
• forsinket ≈ for-SING-ked or for-SEN-ged depending on how detailed the pronunciation is described

About ø:

• It is pronounced with rounded lips.
• It is somewhat like saying eh or uh while rounding your lips.

A learner-friendly approach is:

• do not pronounce prøver like English prover
• try to make the middle vowel more rounded and fronted

Exact pronunciation varies by accent, but recognizing ø as a special Danish vowel is the important first step.

Because Danish spelling traditionally uses commas before subordinate clauses, and hvorfor bussen er forsinket is a subordinate clause.

So the sentence is divided like this:

• Jeg prøver at finde ud af,
• hvorfor bussen er forsinket.

In English, punctuation rules are a bit different, but in Danish this comma is very normal.

The sentence can be broken into three parts:

1. Jeg prøver
   = I am trying

2. at finde ud af
   = to find out

3. hvorfor bussen er forsinket
   = why the bus is delayed

So the full structure is:

• subject + finite verb + infinitive phrase + embedded question

That makes it a very useful model sentence for learners, because you can reuse it easily:

• Jeg prøver at finde ud af, hvor han bor. = I’m trying to find out where he lives.
• Jeg prøver at finde ud af, hvad det betyder. = I’m trying to find out what it means.
• Jeg prøver at finde ud af, om de kommer. = I’m trying to find out whether they are coming.