Når ringeklokken ringer sent om aftenen, tror jeg altid, at det er en levering.

Here når means when / whenever in a general, repeated sense.

The sentence is talking about something that tends to happen:

• Når ringeklokken ringer sent om aftenen ... = whenever the doorbell rings late in the evening

A native English speaker might be tempted to use if, but Danish usually uses når for things that regularly happen or are expected to happen.

Use hvis for a more uncertain or hypothetical if:

• Hvis ringeklokken ringer, åbner jeg ikke. = If the doorbell rings, I won’t open.

So in this sentence, når is the natural choice because it describes a recurring situation.

Because Danish forms compound nouns very freely.

Ringeklokke is a compound noun:

• ringe = to ring / call
• klokke = bell

Together, ringeklokke means doorbell.

Then -n is added for the definite form:

• en ringeklokke = a doorbell
• ringeklokken = the doorbell

English often writes similar ideas as two words, but Danish usually prefers one compound word.

It may feel repetitive to an English speaker, but it is completely normal in Danish.

• ringeklokken = the doorbell
• ringer = rings / is ringing

So literally it is the doorbell rings.

This is no stranger than English sentences like:

• The bell rings
• The phone is ringing

The noun and verb happen to come from the same root, but that is not a problem in Danish.

This is because Danish follows the V2 rule in main clauses.

The sentence begins with a subordinate clause:

• Når ringeklokken ringer sent om aftenen

After that, the main clause starts. In Danish main clauses, the finite verb usually comes in second position, so you get:

• tror jeg altid

not:

• jeg tror altid

The structure is:

• fronted element: Når ringeklokken ringer sent om aftenen
• finite verb: tror
• subject: jeg
• adverb: altid

This is a very important Danish word order pattern.

It means late in the evening.

Breakdown:

• sent = late
• om aftenen = in the evening

So:

• sent om aftenen = late in the evening

This is a very natural Danish way to express time.

Because om aftenen and i aften mean different things.

• om aftenen = in the evening, evenings, in the evenings, as a general time period
• i aften = this evening / tonight

In your sentence, the speaker is describing a general habit or repeated situation, so om aftenen is correct.

Compare:

• Når ringeklokken ringer sent om aftenen ... = When the doorbell rings late in the evening ...
• Ringeklokken ringer i aften. = The doorbell is ringing tonight / will ring tonight.

That is normal in Danish with parts of the day after certain prepositions.

Danish often uses the definite form in expressions like:

• om morgenen = in the morning
• om dagen = during the day
• om aftenen = in the evening
• om natten = at night

So this is not talking about the evening in a special sense. It is just the normal idiomatic form.

The comma after aftenen marks the end of the opening subordinate clause:

• Når ringeklokken ringer sent om aftenen, ...

That comma is very standard.

The comma before at depends a bit on comma style in Danish:

• tror jeg altid, at det er en levering
• tror jeg altid at det er en levering

Both can be seen, depending on whether someone uses the traditional grammatical comma or the newer style.

So:

• the comma after aftenen is expected
• the comma before at may vary

Here at means that.

It introduces a subordinate clause after tror:

• tror jeg altid, at det er en levering
• literally: I always think that it is a delivery

In English, that is often optional, and Danish can sometimes omit at too, especially in speech or informal writing:

• tror jeg altid, det er en levering

But including at is perfectly normal and often clearer.

Here det means it.

It refers to the situation or thing at the door:

• I always think that it is a delivery

This is similar to English, where it can refer to something not yet specifically identified.

So det does not mean a concrete previously mentioned noun here. It is just the natural pronoun for identifying what the ringing probably means.

Because the speaker means a delivery, not the delivery.

• en levering = a delivery
• leveringen = the delivery

The indefinite form shows that the speaker is making a general assumption:

• I always think it’s a delivery

If you said leveringen, it would sound like a specific expected delivery that both speaker and listener already know about.

Literally, levering means delivery.

In context, it can suggest:

• a delivery arriving
• a package being delivered
• the event of someone bringing something

It does not literally mean the delivery person, although in everyday understanding that may be what the speaker has in mind.

If you specifically want to say delivery person / courier, Danish might use words like:

• et bud
• en pakkebud or similar context-based wording

But in this sentence, en levering is natural because the speaker is thinking about the event: it’s probably a delivery.

Because the sentence describes a habitual reaction.

It is not about one single event. It means something like:

• whenever this happens, I have this thought

So Danish uses the present tense:

• ringer
• tror
• er

English does the same in general statements:

• When the doorbell rings late in the evening, I always think it’s a delivery.

Altid means always, and its position is very natural here.

In a main clause, sentence adverbs like altid, ofte, ikke, måske often come after the subject when the finite verb is in second position:

• tror jeg altid

So the order is:

• tror = finite verb
• jeg = subject
• altid = adverb

This is standard Danish word order.

Yes, very often.

You can say:

• Når ringeklokken ringer sent om aftenen, tror jeg altid, at det er en levering.
• Når ringeklokken ringer sent om aftenen, tror jeg altid, det er en levering.

Both are natural. Keeping at makes the structure a little more explicit. Leaving it out can sound slightly more conversational.

No, Danish speakers may also use dørklokke.

Both are understandable:

• ringeklokke
• dørklokke

Depending on the speaker and region, one may feel more common than the other. In your sentence, ringeklokken is completely natural.