Hvis sløjfen går op, binder jeg en ny sløjfe, før gæsterne kommer.

Because Danish follows the V2 rule in main clauses: the finite verb usually comes in the second position.

Here, the sentence begins with the subordinate clause Hvis sløjfen går op. After that whole clause, the main clause starts, and the finite verb must come first:

• Hvis sløjfen går op, binder jeg en ny sløjfe ...

So the structure is:

• subordinate clause first
• then finite verb
• then subject

This is very common in Danish:

• Når jeg kommer hjem, laver jeg mad.
• Hvis det regner, bliver vi inde.

If the main clause came first, you would say:

• Jeg binder en ny sløjfe, hvis sløjfen går op.

Then jeg binder is correct, because nothing has been moved in front of the main clause.

Here går op means something like comes undone, loosens, or unties itself.

Literally, gå op can mean many things in Danish depending on context, such as:

• open up
• go up
• work out / make sense
• come undone

In this sentence, because we are talking about a sløjfe (a bow), går op means the bow comes loose or unties.

So this is a very context-dependent expression. A learner should treat gå op as a useful multi-word expression rather than translating gå and op separately every time.

Danish often uses the present tense to talk about the future, especially when the future event is understood from context.

So:

• før gæsterne kommer

literally uses present tense, but it means before the guests come / before the guests arrive in a future sense.

This works much like English in sentences such as:

• I’ll call you when she arrives.
• We’ll leave before they come.

Danish does this very naturally with time clauses introduced by words like:

• når = when
• før = before
• efter = after
• hvis = if

Gæsterne is the definite plural form, meaning the guests.

The forms are:

• en gæst = a guest
• gæsten = the guest
• gæster = guests
• gæsterne = the guests

In Danish, definiteness is often shown by adding an ending to the noun, rather than using a separate word like the.

So:

• før gæsterne kommer = before the guests arrive

This tells us the speaker has specific guests in mind.

A sløjfe is a bow, like the kind tied with loops, for example on:

• shoelaces
• ribbons
• clothing
• gift wrapping

A knude is a knot more generally.

So in this sentence, sløjfe is used because we are talking about something tied as a bow, not just any knot.

For example:

• en sløjfe i håret = a bow in the hair
• en knude på snoren = a knot in the string

Danish often repeats nouns where English might prefer a pronoun, especially when clarity matters.

So this is perfectly natural:

• Hvis sløjfen går op, binder jeg en ny sløjfe ...

The first sløjfen refers to the existing bow.
The second en ny sløjfe means a new bow.

A pronoun would be possible in some contexts, but repeating the noun here is clear and idiomatic. It also highlights that the speaker will tie another / new bow.

En ny sløjfe means a new bow.

The word ny agrees with the common-gender noun sløjfe, and because the noun is indefinite singular, the structure is:

• en
  • adjective + noun

So:

• en ny sløjfe

Compare:

• en rød bil = a red car
• en stor taske = a big bag

If it were definite, the structure would change:

• den nye sløjfe = the new bow

That is a very common pattern in Danish.

Because hvis and før introduce subordinate clauses, and subordinate clauses normally keep the order subject + verb.

So we get:

• Hvis sløjfen går op
• før gæsterne kommer

Notice:

• sløjfen går
• gæsterne kommer

No inversion happens there.

The inversion happens in the main clause after a fronted element:

• Hvis sløjfen går op, binder jeg ...

So a useful contrast is:

• Hvis sløjfen går op, binder jeg en ny sløjfe.
• Jeg binder en ny sløjfe, hvis sløjfen går op.

The subordinate clause itself does not change word order just because it starts with hvis or før.

Not in the same way. Danish does have many verb + particle combinations, but they do not behave exactly like German separable verbs.

In this sentence, går op stays together in the clause:

• sløjfen går op

In other contexts, Danish can place adverbs and particles differently, but it is usually best for learners to memorize common combinations like:

• gå op
• tage af
• finde ud af
• komme ind

as fixed expressions with meanings that depend on context.

So yes, it is a verb + particle combination, but you should not assume it works exactly like German.

The commas separate the clauses:

• Hvis sløjfen går op, = subordinate clause
• binder jeg en ny sløjfe, = main clause
• før gæsterne kommer. = subordinate time clause

So the sentence has three parts, and the commas mark those boundaries.

Danish comma rules can feel tricky because there are slightly different comma traditions, but in learner materials you will very often see commas used to make clause structure clear.

At the very least, it is helpful to recognize that the commas show:

1. the end of the if-clause
2. the start of the before-clause

Yes. Danish is flexible about moving adverbial clauses to the front. For example:

• Før gæsterne kommer, binder jeg en ny sløjfe, hvis sløjfen går op.

That is grammatically possible, although it sounds a bit heavier.

You could also say:

• Hvis sløjfen går op, binder jeg en ny sløjfe før gæsterne kommer.

In all these versions, the main thing to remember is:

• if a clause comes first, the following main clause uses inversion
• so you still get binder jeg, not jeg binder

Two things often trouble English speakers here:

• øj in sløjfen
• æ in gæsterne

A rough guide:

• sløjfen: the øj is somewhat like the vowel glide in English boy, but with a more rounded starting point
• gæsterne: æ is somewhat like the vowel in cat, though not exactly the same

Also, Danish unstressed endings are often reduced in natural speech, so:

• sløjfen
• gæsterne

may sound less fully pronounced than you expect from the spelling.

The best approach is to listen to native audio and repeat whole chunks:

• Hvis sløjfen går op
• før gæsterne kommer

rather than trying to build the pronunciation sound by sound at first.