Hvis anklen stadig er forstuvet overmorgen, ringer hun til lægen igen.

Use hvis when you mean a real condition: if X happens, Y happens.

So here:

Hvis anklen stadig er forstuvet overmorgen, ringer hun til lægen igen.

means a condition: if the ankle is still sprained the day after tomorrow, then she calls the doctor again.

Om is usually used for whether/if in indirect questions, for example:

Jeg ved ikke, om hun ringer.
= I don’t know whether she is calling.

So in this sentence, hvis is the correct choice.

This is a very common Danish word-order pattern.

The sentence starts with a subordinate clause:

Hvis anklen stadig er forstuvet overmorgen, ...

After that comes the main clause. In a Danish main clause, the finite verb normally has to be in the second position. Because the hvis-clause takes up the first slot, the verb comes before the subject:

..., ringer hun til lægen igen.

If the main clause stood alone, it would be:

Hun ringer til lægen igen.

So the inversion happens because the sentence begins with the conditional clause.

Danish often uses the present tense to talk about the future when the time is already clear from context.

Here, overmorgen already tells you this is about the future, so ringer is perfectly natural.

Danish does this a lot:

Jeg kommer i morgen.
= I’m coming tomorrow.

You could sometimes use vil ringe instead, but that adds a slightly different nuance, such as intention or prediction. The simple present is very normal here.

Anklen is the definite singular form of ankel:

• en ankel = an ankle
• anklen = the ankle

The ending -en is the usual definite ending for many common-gender nouns.

Also, Danish often uses the definite form with body parts where English may prefer a possessive:

• Hun vasker hænderne. = She washes her hands.
• Anklen can often imply her ankle if the context makes that clear.

Forstuvet is the past participle of forstuve, but in this sentence it functions like an adjective.

So:

anklen er forstuvet
literally = the ankle is sprained

This is similar to English, where sprained can describe a state.

Compare:

• Hun har forstuvet anklen. = She has sprained her ankle.
• Anklen er forstuvet. = The ankle is sprained.

The first focuses on the action/result; the second describes the condition of the ankle.

Because this is a subordinate clause.

In Danish subordinate clauses, adverbs like stadig, ikke, nok, and similar words often come before the finite verb.

So you get:

Hvis anklen stadig er forstuvet ...

But in a main clause, you would usually say:

Anklen er stadig forstuvet.

This difference between main-clause and subordinate-clause word order is one of the most important things to notice in Danish.

Because Danish normally uses overmorgen on its own.

• i morgen = tomorrow
• i overmorgen is not standard here
• overmorgen = the day after tomorrow

So:

overmorgen
is the normal form, without an added preposition.

Yes. Danish allows some flexibility with time expressions.

The given sentence says:

Hvis anklen stadig er forstuvet overmorgen, ...

You could also say:

Hvis anklen overmorgen stadig er forstuvet, ...

Both are grammatical. The difference is mostly about rhythm and emphasis.

The original version is very natural and places overmorgen near the end of the condition, almost like if the ankle is still sprained by the day after tomorrow.

Because the Danish verb is ringe til nogen = to call someone.

English says:

call the doctor

But Danish normally says:

ringe til lægen

So the preposition til is just part of the standard pattern for this verb.

A useful contrast:

• ringe til lægen = call the doctor (phone the doctor)
• ringe efter lægen = call for the doctor / send for the doctor

So til is the right choice here.

Igen means again.

Putting it at the end is very natural here:

ringer hun til lægen igen

That is the neutral, idiomatic order.

If you move igen, the sentence may still be possible, but it can sound marked or shift the emphasis slightly. For a learner, the safest pattern is to treat final position as the normal one in sentences like this.

Yes. The first part is a subordinate clause introduced by hvis, and it is followed by the main clause:

Hvis anklen stadig er forstuvet overmorgen, ringer hun til lægen igen.

So the comma marks the boundary between the conditional clause and the main clause.

This is also helpful because the word order changes right after the comma: the main clause begins with ringer hun, not hun ringer.