Mågen flyver over havnen, når færgen sejler ud.

In Danish, the definite article is usually attached to the end of the noun.

So:

• måge = seagull

• mågen = the seagull

• havn = harbor

• havnen = the harbor

• færge = ferry
• færgen = the ferry

These are all common gender nouns, so their singular definite ending is -en. If they were neuter nouns, the definite ending would usually be -et instead.

Here, når means when.

It is commonly used for:

• something that happens regularly or habitually
• something expected in the future

So this sentence suggests a repeated or typical situation: whenever the ferry goes out, the seagull flies over the harbor.

A useful contrast:

• når = when, whenever
• hvis = if
• da = when, but usually for a single event in the past

Danish often uses the present tense where English also uses the present for general truths, habits, and scheduled or regular events.

So:

• flyver = flies / is flying
• sejler = sails / is sailing

In this sentence, the present tense most naturally gives a habitual or general meaning: this is what happens when the ferry leaves.

The verb forms are:

• at flyve → flyver
• at sejle → sejler

Because når introduces a subordinate clause.

In Danish, subordinate clauses normally have the order:

conjunction + subject + verb

So:

• når færgen sejler ud = when the ferry sails out

This is different from main clauses, where Danish often follows the verb-second pattern.

Compare:

• Færgen sejler ud. = The ferry sails out.
• Nu sejler færgen ud. = Now the ferry sails out.

But after når, you keep the subject before the verb:

• når færgen sejler ud

Sejler ud means sails out, goes out by boat, or more naturally in context, departs.

The verb is:

• at sejle = to sail

The particle:

• ud = out

Together, they express outward movement. This works a lot like English verb-particle combinations such as go out or sail out.

So færgen sejler ud is not just about floating on water in general. It specifically suggests the ferry is heading out from the harbor.

Over havnen means over the harbor.

For a bird, over is the natural word if it is flying above the harbor area.

Depending on context, over can mean:

• physically above
• across
• over the area of

Here, it most likely means the seagull is flying above or across the harbor space.

These vowels are often tricky for English speakers.

• å in Mågen is roughly like the vowel in British thought for many speakers, though not exactly the same.
• æ in færgen is somewhat like the vowel in cat, but again not identical.
• y in flyver is a front rounded vowel that English does not really have. A common trick is to say ee while rounding your lips.

The exact pronunciation varies by accent, and Danish vowels are famous for being difficult, so it is normal if these sounds take time.

Because når færgen sejler ud is a subordinate clause, and many Danish writers place a comma before subordinate clauses.

You may also see the sentence written without that comma, depending on comma style:

• Mågen flyver over havnen, når færgen sejler ud.
• Mågen flyver over havnen når færgen sejler ud.

Both can be acceptable in modern Danish. The meaning does not change.

Yes. That is a perfectly natural alternative.

When the når clause comes first, the main clause changes word order because of Danish verb-second rules:

• Når færgen sejler ud, flyver mågen over havnen.

Notice that it becomes:

• flyver mågen
• not mågen flyver

So the two versions are both correct:

• Mågen flyver over havnen, når færgen sejler ud.
• Når færgen sejler ud, flyver mågen over havnen.

The difference is mainly one of emphasis and sentence flow.