Learn Hardcore Danish: Hvis hendes hals gør meget ondt, ringer hun til sin læge. - If her throat hurts a lot, she calls her doctor.

hendes = her (non‑reflexive, does not have to refer to the subject of the clause)
sin/sit/sine = her/his/its/their own (reflexive, refers back to the subject of that clause)

In your sentence:

Subordinate clause: Hvis hendes hals gør meget ondt
- Subject = hendes hals (the throat)
- The owner of the throat is she, but she is not the grammatical subject here – hals is.
- Therefore you must use hendes, not sin.
Main clause: ringer hun til sin læge
- Subject = hun
- The owner of the doctor is the same person as hun.
- Therefore you use sin (reflexive) to show the doctor is her own doctor.

So:

Hvis hendes hals gør meget ondt → correct
Hvis sin hals gør meget ondt → incorrect
… ringer hun til sin læge → correct, and clearly means her own doctor

Why is the word order ringer hun and not hun ringer after the comma?

In main clauses, Danish has V2 word order: the finite verb must be in second position.

When a subordinate clause comes first, it counts as the first element of the main clause. The main-clause verb still has to be second, so the subject moves after the verb:

Neutral order (no fronted clause):
- Hun ringer til sin læge. → Subject (hun) first, then verb (ringer).
With a fronted element (the hvis‑clause):
- Hvis hendes hals gør meget ondt, ringer hun til sin læge.
  - 1st element: Hvis hendes hals gør meget ondt
  - 2nd element: ringer (the finite verb)
  - 3rd element: hun (the subject)

So ringer hun is required here because of the V2 rule in Danish main clauses.

Why does Danish say hals gør ondt? Could I say something like har ondt i halsen instead?

Both patterns exist; they are just different idioms:

[Body part] + gør ondt
- Hendes hals gør meget ondt.
- Literally: Her throat does a lot of hurt → Her throat hurts a lot.
have ondt i + [body part]
- Hun har meget ondt i halsen.
- Literally: She has a lot of pain in the throat → She has a bad sore throat / Her throat hurts a lot.

Your sentence uses pattern 1. Pattern 2 is very common and very natural too. So you could also say:

Hvis hun har meget ondt i halsen, ringer hun til sin læge.

Meaning-wise they are practically the same; pattern 2 is probably what you’ll hear most in everyday speech.

What exactly does meget ondt mean here? Could I also say rigtig ondt or virkelig ondt?

meget is a general intensifier meaning a lot / very.

meget ondt → a lot of pain / hurts a lot

You can use other common intensifiers with ondt:

rigtig ondt – really hurts (quite colloquial)
virkelig ondt – truly / really hurts
så ondt – so much (often emotional or emphatic)
temmelig ondt – rather / quite a bit (milder)

So you could also say:

Hvis hendes hals gør rigtig ondt, ringer hun til sin læge.
Hvis hendes hals gør virkelig ondt, ringer hun til sin læge.

The basic structure and grammar stay the same; only the degree and tone change.

Why is there a comma in the middle of the sentence?

The first part of the sentence is a subordinate clause introduced by hvis, and the second part is the main clause.

Danish comma rules say that when a subordinate clause comes before the main clause, you put a comma between them:

Hvis hendes hals gør meget ondt, ringer hun til sin læge.

So the comma simply marks the boundary between:

Subordinate clause: Hvis hendes hals gør meget ondt
Main clause: ringer hun til sin læge

Why are gør and ringer in the present tense if this is about a possible future situation?

Danish, like English, commonly uses the present tense to talk about future situations in hvis‑clauses and their main clauses:

Hvis hendes hals gør meget ondt, ringer hun til sin læge.
→ If her throat hurts a lot, she will call her doctor.

This is parallel to English:

If it rains tomorrow, I stay at home. / … I’ll stay at home.

You can add a future auxiliary (vil) in Danish:

Hvis hendes hals gør meget ondt, vil hun ringe til sin læge.

This is also correct, but often not necessary. The plain present is very natural and slightly more neutral in this type of conditional sentence.

Why is it ringer … til sin læge and not just ringer sin læge?

In Danish, ringe meaning to call (on the phone) is normally used with a preposition:

ringe til nogen – call someone
- Hun ringer til sin læge. – She calls her doctor.

Another pattern is:

ringe nogen op – call someone up
- Hun ringer sin læge op.

But ringe nogen (without til or op) is not standard Danish in this sense.

So in your sentence, because you are not using op, you must keep til:

… ringer hun til sin læge. ✅
… ringer hun sin læge. ❌

Why is it hendes hals and not hendes halsen?

In Danish, you cannot combine:

a possessive pronoun (min, din, hans, hendes, sin, vores, jeres, deres)
with the definite suffix (‑en, ‑et, ‑ene) on the noun.

So you choose one of these patterns:

hendes hals – her throat (possessive, noun in indefinite form)
halsen – the throat (definite form, no possessive)

You cannot say:

✗ hendes halsen

So:

hendes hals → correct
halsen → correct in another context
hendes halsen → ungrammatical

Can I use når instead of hvis here? What is the difference?

hvis and når both translate to if/when, but they are not interchangeable.

hvis = if, for conditions that may or may not happen.
når = when / whenever, for things that are expected or seen as certain or habitual.

In your sentence:

Hvis hendes hals gør meget ondt, ringer hun til sin læge.
→ It is conditional: If it happens that her throat hurts a lot, then she calls her doctor.

If you said:

Når hendes hals gør meget ondt, ringer hun til sin læge.

it would sound more like Whenever / every time her throat hurts a lot, she calls her doctor – suggesting this is a regular or expected situation.

So hvis is the more natural choice for a normal one‑time condition.

Could I say Hvis hendes hals gør meget ondt, vil hun ringe til sin læge? Is that more correct?

Yes, that sentence is grammatically correct:

Hvis hendes hals gør meget ondt, vil hun ringe til sin læge.

Difference in nuance:

ringer hun – simple, neutral conditional; very common and natural.
vil hun ringe – can:
- stress the future a bit more, or
- suggest a bit more intention / willingness (she will want to call).

In everyday Danish, people often stick to the simple present (ringer hun) in this kind of hvis‑sentence, just like in English: If it hurts, she calls…

What is the difference between læge and doktor in Danish?

In modern Danish:

læge is the normal word for a medical doctor.
- Jeg skal til lægen. – I’m going to the doctor.
doktor is:
- a formal title (academic: PhD, MD, etc.), or
- used in set expressions or older style.

If you are talking about your GP or a medical doctor you see when you are sick, you almost always use læge, not doktor, in everyday speech.

So your sentence uses the natural everyday word:

… ringer hun til sin læge.

Why can’t I say Hvis sin hals gør meget ondt?

There are two problems with Hvis sin hals gør meget ondt:

Reflexive rule:
sin/sit/sine must refer back to the subject of the same clause.
In sin hals, the grammatical subject would be sin hals itself – but sin cannot refer to something inside its own noun phrase. It needs an external subject (like hun) within the same clause.
In your actual sentence, the subject of the subordinate clause is hendes hals (or halsen), not hun. The owner (she) is not the subject there, so you must use hendes, not sin.

Therefore:

Hvis hendes hals gør meget ondt, … ✅
Hvis sin hals gør meget ondt, … ❌

To use sin, the subject of that clause would have to be the person herself, for example:

Hvis hun gør sin hals våd, … (still odd content‑wise, but grammatically OK: If she makes her own throat wet…)