Hvis du vil være mere punktlig, bør du gå hjemmefra ti minutter tidligere.

Hvis means if. It introduces a condition: if you want to be more punctual, then you should leave home ten minutes earlier.

In Danish, the then part is often understood and does not have to be stated explicitly.

This is because Danish uses different word order in subordinate clauses and main clauses.

• After hvis, you have a subordinate clause, so the order is the normal subject + verb: du vil

• The second part is the main clause. In Danish main clauses, the finite verb usually comes in second position. Since the whole Hvis du vil være mere punktlig clause comes first, the verb bør must come before the subject du:

• Hvis du vil være mere punktlig, bør du gå hjemmefra ...
• Compare with: Du bør gå hjemmefra ...

Because the sentence has two clauses, and each clause needs its own subject.

So even though both clauses refer to the same person, Danish still says:

• Hvis du vil ...
• bør du ...

You cannot leave out the second du.

After modal verbs and similar verbs like vil, Danish normally uses the bare infinitive, without at.

So you say:

• vil være
• kan gå
• skal spise
• bør tage

not:

• vil at være
• kan at gå

So vil være is the correct form.

Here vil is best understood as want to.

So Hvis du vil være mere punktlig means If you want to be more punctual.

In other contexts, vil can also mean future will, but here the meaning is about intention or desire, not simple future time.

Punktlig means punctual or on time.
Mere punktlig means more punctual.

Danish can form comparatives in two ways:

• with an ending, like tidlig → tidligere
• with mere + adjective, especially with longer or less everyday adjectives

With punktlig, mere punktlig sounds much more natural than punktligere, which would sound awkward to most speakers.

Bør means should or ought to. It gives advice or a recommendation.

It is softer than a strong command. So the sentence is not ordering someone; it is advising them.

In tone, bør can sound a little more formal or written than everyday spoken Danish.

Yes, but the meaning changes a bit.

• bør = should / ought to; advice
• burde = also should, often common in speech and sometimes a bit softer
• skal = must / have to / are supposed to; stronger and more obligatory

So:

• Du bør gå hjemmefra tidligere = advice
• Du burde gå hjemmefra tidligere = also advice, very natural in speech
• Du skal gå hjemmefra tidligere = stronger, more like an instruction

In this sentence, gå hjemmefra means leave home or set off from home.

It does not necessarily mean that you are walking on foot. You could leave home by car, bike, bus, or train and still use gå hjemmefra.

So here it is best understood idiomatically as leave home.

Because hjemmefra is a fixed adverb meaning from home.

Danish often writes these directional adverbs as one word:

• hjemmefra = from home
• udefra = from outside
• ovenfra = from above

So gå hjemmefra is the normal spelling.

Tidligere means earlier and works well when you are comparing with an understood usual time.

So gå hjemmefra ti minutter tidligere means leave home ten minutes earlier than you normally do.

Før usually needs a clearer reference point, such as:

• ti minutter før mødet = ten minutes before the meeting
• før klokken otte = before eight o’clock

So in this sentence, tidligere is the more natural choice.

Here it functions like an adverb, because it describes the action gå hjemmefra: it tells you when you should leave.

It comes from tidlig = early, and tidligere = earlier.

In Danish, the same comparative form is often used whether it is acting more like an adjective or an adverb.

Possibly, yes. Danish can say:

• Hvis du vil være mere punktlig, bør du gå hjemmefra ...
• Hvis du vil være mere punktlig, så bør du gå hjemmefra ...

Both are correct. The version without så is completely normal, especially in writing.

Yes, it is natural Danish.

A Dane might also say something like:

• Hvis du vil komme mere til tiden, bør du gå hjemmefra ti minutter tidligere.
• Hvis du vil være mere punktlig, burde du tage hjemmefra ti minutter tidligere.

But the original sentence is clear, correct, and natural.