Først når læsemålet er klart, ændrer vi bogvalget.

Først når is a fixed expression meaning only when.

So:

• Først når læsemålet er klart = Only when the reading goal is clear
• It introduces a condition: the action in the main clause happens not before that point.

This is a very common Danish pattern:

• Først når du er færdig, kan vi gå. = Only when you are finished can we leave.

It is stronger and more specific than just når (when).

Because the sentence begins with a subordinate clause:

• Først når læsemålet er klart, ...

In Danish main clauses, the finite verb normally comes in second position. This is often called the V2 rule.

So after the opening clause, the main clause must begin with the verb:

• Først når læsemålet er klart, ændrer vi bogvalget.

Not:

• Først når læsemålet er klart, vi ændrer bogvalget.

You can compare:

• Vi ændrer bogvalget.
• I dag ændrer vi bogvalget.
• Når tiden er inde, ændrer vi bogvalget.

The thing placed first changes, but the finite verb still stays in second position in the main clause.

Yes, but in this sentence it works inside the fixed expression først når, which means only when.

On its own, når often means when in general or repeated situations:

• Når jeg læser, drikker jeg kaffe. = When I read, I drink coffee.

In your sentence, the full idea is conditional and time-related:

• Først når ... = Only when ...

So translating når by itself as when is fine, but here you should understand the whole phrase together.

Yes. Læsemålet is a single compound noun, which is very normal in Danish.

It is made from:

• læse = to read
• mål = goal
• -et = the definite ending (the)

So:

• læsemål = reading goal
• læsemålet = the reading goal

Danish uses compounds much more than English. Where English often writes two words, Danish often prefers one.

Because klart agrees with læsemålet, which is a neuter noun.

In Danish, adjectives used after er often agree with the noun:

• common gender singular: klar
• neuter singular: klart
• plural / definite contexts: often klare

Since mål is a neuter noun (et mål), we get:

• læsemålet er klart

Compare:

• planen er klar = the plan is clear
• målet er klart = the goal is clear

Bogvalget means the book choice or the choice of book(s).

It is formed like this:

• bogvalg = book choice / choice of book
• bogvalget = the book choice / the choice of book

In Danish, the definite article is usually added as an ending:

• en bog = a book

• bogen = the book

• et valg = a choice
• valget = the choice

So bogvalget is the normal way to say the choice of book(s) as one compound noun.

It means the choice of book or which book to choose.

Literally, it is built as book + choice, but in natural English you would usually say:

• the choice of book
• which book we choose
• sometimes the book selection, depending on context

So yes, it is a compound noun, but its natural meaning is broader than the literal word-for-word breakdown.

Because the sentence is describing a state, not the process of changing into that state.

• er klart = is clear
• bliver klart = becomes clear

Your sentence means that once the reading goal is clear, then we change the book choice.

If you said:

• Først når læsemålet bliver klart ...

that would focus more on the moment it becomes clear. Possible in some contexts, but slightly different in meaning.

The comma separates the subordinate clause from the main clause:

• Først når læsemålet er klart, = subordinate clause
• ændrer vi bogvalget. = main clause

In standard Danish, this comma is normal and helpful because it shows where the introductory clause ends.

For learners, it is especially useful because it also helps you see why the word order changes in the main clause.

Yes. You could say:

• Vi ændrer først bogvalget, når læsemålet er klart.

This means essentially the same thing:

• We only change the book choice when the reading goal is clear.

The difference is mainly emphasis:

• Først når læsemålet er klart, ændrer vi bogvalget.

  • stronger focus on the condition
  • more formal or emphatic

• Vi ændrer først bogvalget, når læsemålet er klart.

  • a little more neutral and straightforward

Yes, it is the same basic word, but the usage is wider.

On its own, først can mean:

• first
• at first
• not until / only then, depending on context

In først når, it does not mean first in a sequence. It means something closer to:

• only when
• not until

So in this sentence, don’t read it as first when in a literal English way. Treat først når as a unit.

It is normal and natural Danish, especially in written or careful spoken language.

It sounds:

• neutral
• slightly structured or deliberate
• not strange at all

Because it uses først når and fronting of the condition, it may sound a bit more thoughtful or emphatic than a simpler version, but it is absolutely standard Danish.