Nogen prøver at stjæle cyklen.

Here, nogen means someone.

In Danish, nogen can sometimes mean someone, anyone, or somebody, depending on the context. In this sentence, because the statement is affirmative, the natural English meaning is someone.

• Nogen ringer på døren. = Someone is ringing the doorbell.
• Er der nogen hjemme? = Is anyone home?

In Danish, prøve often takes at + infinitive when it means to try to do something.

So:

• prøver at stjæle = is trying to steal

This is very common in Danish:

• Jeg prøver at sove. = I’m trying to sleep.
• Hun prøver at lære dansk. = She’s trying to learn Danish.

So the at here works like to in English.

Prøver is the present tense of prøve.

• at prøve = to try
• prøver = try / tries / am trying / is trying / are trying

Danish present tense is often used where English might use either the simple present or the present continuous, depending on context.

So Nogen prøver at stjæle cyklen can correspond to:

• Someone tries to steal the bike
• Someone is trying to steal the bike

In most real situations, the second English version is the more natural one.

Danish usually does not use a special continuous form the way English does.

English distinguishes:

• Someone tries to steal the bike
• Someone is trying to steal the bike

But Danish often uses the same present tense form for both ideas:

• Nogen prøver at stjæle cyklen

If you want to make the ongoing action especially clear in Danish, context usually does the job. Danish can sometimes use other structures, but the plain present tense is normal here.

Cyklen means the bike. Danish usually marks definiteness by adding an ending to the noun.

• en cykel = a bike
• cyklen = the bike

This is called the suffixed definite article.

So instead of putting a separate word before the noun, Danish often attaches the definite ending directly to the noun:

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

You can use den cykel, but usually only when there is an added description or special emphasis, such as:

• den røde cykel = the red bike

Because cykel is a common gender noun in Danish.

Danish nouns are usually either:

• common gender (en-words)
• neuter gender (et-words)

Since it is:

• en cykel = a bike

the definite form becomes:

• cyklen = the bike

Compare:

• en stol → stolen
• et hus → huset

So the ending depends on the noun’s gender.

Here, nogen is treated as singular in meaning: someone.

That is why the sentence corresponds to English someone is trying..., not some people are trying...

However, Danish verbs do not change form for singular and plural the way English verbs sometimes do. So you would still see the same verb form:

• Nogen prøver...
• De prøver...

The verb prøver stays the same.

The basic form is at stjæle, meaning to steal.

In the sentence, it appears as an infinitive after at:

• prøver at stjæle = tries/is trying to steal

Some useful forms are:

• at stjæle = to steal
• stjæler = steal / steals / is stealing
• stjal = stole
• har stjålet = have/has stolen

So this sentence literally has the structure:

• someone + tries + to steal + the bike

For many English speakers, stjæle looks harder than it really is.

A few points:

• æ is a Danish vowel sound somewhat like the vowel in English cat, though not exactly the same.
• The beginning stj- is pronounced more smoothly than it looks in writing.
• The word is roughly pronounced something like STYE-leh or STYEH-leh, but that is only an approximation.

A very rough pronunciation of the whole sentence might be:

• NO-gen PRØ-ver at STYE-leh SYK-len

But it is best to listen to native audio, because Danish pronunciation often differs a lot from the spelling.

Usually, yes, but it can cover a couple of related ideas.

Prøve can mean:

1. to try / attempt

   • Jeg prøver at forstå. = I’m trying to understand.

2. to test / check

   • Prøv mikrofonen. = Test the microphone.

3. to try on

   • Jeg prøver jakken. = I’m trying on the jacket.

In your sentence, it clearly means to try / attempt.

Yes. A close synonym would be:

• Nogen forsøger at stjæle cyklen.

Here, forsøger also means is trying / attempts.

The difference is mainly style:

• prøver at is very common and everyday
• forsøger at can sound a bit more formal or deliberate

Both are correct, but prøver at is very natural in ordinary speech.

The word order is the normal Danish order for a main clause:

• Nogen = subject
• prøver = finite verb
• at stjæle = infinitive phrase
• cyklen = object

So the structure is:

• Subject + verb + infinitive phrase + object

This is straightforward main-clause word order in Danish. If you moved another element to the front, Danish would usually place the finite verb in second position:

• Nu prøver nogen at stjæle cyklen. = Now someone is trying to steal the bike.

That verb-second pattern is very important in Danish.