Det lyder, som om kuglereturen virker igen.

In Det lyder ..., det is a dummy subject, just like it in English It sounds like ....

It does not refer to a specific thing here. Danish often uses det in general statements about how something seems, sounds, looks, etc.

So:

• Det lyder ... = It sounds ...
• Det ser ud ... = It looks ...

Lyder is the present tense of at lyde.

In this sentence, it means sounds in the sense of seems from what I hear / from the information available.

So it is not necessarily about an actual physical sound. It is more like:

• It sounds like ...
• It seems that ...

Som om means as if or like in this kind of sentence.

So:

• Det lyder, som om ... = It sounds as if ... / It sounds like ...

It introduces the idea that this is the speaker’s impression, not a hard factual statement.

A few similar examples:

• Det ser ud, som om det regner. = It looks as if it’s raining.
• Det virker, som om hun er træt. = It seems as if she is tired.

The comma separates the main clause from the clause introduced by som om.

• Main clause: Det lyder
• Following clause: som om kuglereturen virker igen

In modern Danish, you may see both:

• Det lyder, som om kuglereturen virker igen.
• Det lyder som om kuglereturen virker igen.

Both are common, depending on comma style. So the comma here is normal, but you may also encounter the sentence without it.

Kuglereturen is a compound noun in the definite singular.

It is built like this:

• kugle = ball
• retur = return
• -en = the definite ending (the)

So the whole word means the ball return.

This is very common in Danish: nouns are often joined into one word, and the definite ending goes on the last part.

For example:

• bil
  • dør = bildør = car door
• bildøren = the car door

Virker is the present tense of at virke, which can mean works, functions, or sometimes seems depending on context.

Here it means is working / is functioning.

So:

• kuglereturen virker igen = the ball return is working again

If you used er, that would just mean is, and it would not express the idea of functioning properly.

Compare:

• Maskinen virker. = The machine works.
• Maskinen er stor. = The machine is big.

Igen means again, and in Danish it often comes late in the clause, especially after the verb.

So:

• kuglereturen virker igen = the ball return works again

This placement is very natural in Danish.

You can think of the structure as:

• subject: kuglereturen
• verb: virker
• adverb: igen

Because after som om, you have a subordinate clause, and subordinate clauses normally keep subject + verb order in Danish.

So:

• som om kuglereturen virker igen
  = as if the ball return is working again

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

Compare:

• Main clause: Nu virker kuglereturen igen.
• Subordinate clause: ... som om kuglereturen virker igen.

That difference is very important in Danish grammar.

Yes, very much so. In sentences like this, som om functions as a set phrase meaning as if.

Learners should usually treat it as one unit:

• Det lyder som om ...
• Det ser ud som om ...
• Det virker som om ...

That makes it easier to remember both the meaning and the word order that follows.

Yes, you could, but the meaning changes slightly.

• Det lyder, som om ... = It sounds as if ...
  This suggests the impression comes from what someone said or from what you heard.
• Det virker, som om ... = It seems as if ...
  This is a bit more general and not tied as closely to sound or reported information.

So your original sentence specifically uses lyder because the speaker is reacting to how the situation sounds.

No. Even though it may look a little similar, the pronunciation is different.

A learner mainly needs to know:

• y in Danish is not like English ee
• lyder has a rounded vowel sound that English does not use in the same way

So it is better to learn it by listening rather than guessing from spelling.

Also, the d in words like lyder is often softer than an English d in actual pronunciation.