Hun lægger sit kørekort i pungen, så hun ikke mister det.

Because Danish uses a reflexive possessive when the owner is the same as the subject of the clause.

Here, the subject is hun and the driving licence belongs to her, so Danish uses sin/sit/sine rather than hendes.

• sin = for common-gender nouns
• sit = for neuter nouns
• sine = for plural nouns

Since kørekort is a neuter noun, it becomes sit kørekort.

Compare:

• Hun lægger sit kørekort i pungen. = She puts her own driving licence in the wallet.
• Hun lægger hendes kørekort i pungen. = She puts another woman’s driving licence in the wallet.

So sit shows that the licence belongs to the same person as hun.

You usually learn the gender together with the noun. A good dictionary will show it.

In Danish, nouns are mainly either:

• common gender: take en
• neuter: take et

et kørekort = a driving licence

Because it is neuter, the reflexive possessive is sit, and the pronoun referring back to it is det:

• sit kørekort
• mister det

So the sentence is internally consistent:

• et kørekort
• sit kørekort
• det

This is a very common Danish learner question.

• lægger comes from at lægge = to lay, put, place something
• ligger comes from at ligge = to lie, be lying, be located

In this sentence, she is actively putting the licence somewhere, so Danish uses lægger:

• Hun lægger sit kørekort i pungen. = She puts her driving licence in the wallet.

If you said ligger, it would describe where something already is:

• Kørekortet ligger i pungen. = The driving licence is in the wallet.

So:

• lægge = movement/placement
• ligge = position/state

Because Danish usually uses the definite form when English would often say the.

• en pung = a wallet
• pungen = the wallet

So:

• i pungen = in the wallet

In many everyday situations, Danish prefers the definite form where English might simply say in her wallet or in the wallet, depending on context.

You could also say:

• i sin pung = in her own wallet

But i pungen sounds completely natural when the context already makes it clear whose wallet it is.

Here så means so that.

The sentence structure is:

• Hun lægger sit kørekort i pungen = She puts her driving licence in the wallet
• så hun ikke mister det = so that she does not lose it

So så introduces a purpose/result clause.

In English, a natural translation would often be:

• She puts her driving licence in her wallet so she doesn’t lose it.
• ...so that she won’t lose it.

So this is not the same as every use of så in Danish. It can mean different things depending on context, such as then, so, or thus, but here it means so that.

Because in subordinate clauses, Danish word order usually places ikke before the finite verb.

The part after så is a subordinate clause:

• så hun ikke mister det

That word order is normal Danish subordinate-clause order:

• subject + ikke
  • verb

So:

• hun ikke mister det

Compare that with a main clause, where ikke often comes after the verb:

• Hun mister ikke det. or more naturally Hun mister det ikke.

A useful rule:

• main clause: verb usually comes before ikke
• subordinate clause: ikke usually comes before the verb

That is why så hun ikke mister det is correct.

Det refers back to sit kørekort.

Since kørekort is a neuter noun (et kørekort), the pronoun used to refer to it is det.

So:

• Hun lægger sit kørekort i pungen, så hun ikke mister det.
• det = kørekortet

If the noun were common gender, Danish would usually use den instead.

Danish often uses the present tense in situations where English may use either the present tense or a future-style meaning.

• hun ikke mister det literally: she does not lose it
• natural English: so she doesn’t lose it or so she won’t lose it

This is normal. Danish does not always need a separate future form here. The present tense often covers that meaning when the context is clear.

So mister is present tense, but in English the best translation may sound slightly future-oriented.

Kørekort is a compound noun:

• køre = to drive
• kort = card

So literally it is something like driving card, but the real meaning is driving licence or driver’s licence.

Compound nouns are extremely common in Danish. English often writes similar ideas as separate words, but Danish often combines them into one word.

Other examples:

• pas = passport
• sygesikringkort = health insurance card
• betalingskort = payment card

So kørekort is a very typical Danish-style compound noun.

Not in the same natural way here.

In this sentence, så hun ikke mister det is the normal way to express so that she doesn’t lose it.

Danish also uses for at for purpose, but it works differently and is usually followed directly by an infinitive phrase, not a full clause with its own subject in the same way.

For example:

• Hun lægger sit kørekort i pungen for ikke at miste det. = She puts her driving licence in the wallet in order not to lose it.

That is also correct and natural.

So you have two good patterns:

• ... så hun ikke mister det = ... so that she doesn’t lose it
• ... for ikke at miste det = ... in order not to lose it

But for at hun ikke mister det would not be the normal choice here.

Yes, in standard Danish punctuation, a comma is normally used before a subordinate clause like this one.

So:

• Hun lægger sit kørekort i pungen, så hun ikke mister det.

The comma helps show that the second part is a dependent clause introduced by så.

Danish comma rules can feel more systematic than English ones, and learners often notice commas before subordinate clauses quite often.