Learn Hardcore Danish: Jeg havde allerede låst døren, før min mor kom hjem. - I had already locked the door before my mother came home.

Past perfect (havde låst) shows an action completed before another past event (kom hjem).
You could also say: Jeg låste døren, før min mor kom hjem. That’s also natural; før already signals the sequence. Past perfect just makes the timeline extra explicit or ties both events to a later past reference point in a narrative.

Where should allerede go, and can it go elsewhere?

In main clauses, sentence adverbs come right after the finite verb: Jeg havde allerede låst døren.
End placement is possible for emphasis/colloquial style: Jeg havde låst døren allerede.
Don’t split the verb and its object with it: avoid Jeg havde låst allerede døren.

Why is it før min mor kom hjem and not før kom min mor hjem?

After a subordinating conjunction like før, Danish uses subordinate-clause word order (no V2): conjunction + subject + (adverbs) + finite verb.
So: før min mor kom hjem is correct; før kom min mor hjem is ungrammatical.
With other conjunctions, the same rule applies, e.g., at jeg ikke har tid (not: at har jeg ikke tid).

Can I put the time clause first?

Yes: Før min mor kom hjem, havde jeg allerede låst døren.
Note the inversion in the main clause after a fronted element: finite verb before subject (havde jeg), because Danish main clauses are V2.

Can I use inden instead of før here?

Yes: ..., inden min mor kom hjem is fine.
Nuance: før compares two events directly; inden can feel more like “before the time when” (a deadline). In everyday Danish, they’re largely interchangeable in this sentence.

What about før end, førend, or før at?

før end is acceptable for emphasis/contrast: Det sker ikke, før end du ringer.
førend is archaic/rare today.
Avoid før at; it’s considered non-standard.

Is the comma before før required?

With the common “start comma” system: yes — ..., før min mor kom hjem.
With the “no start comma” system: omit it — Jeg havde allerede låst døren før min mor kom hjem.
Pick one system and be consistent.

Why is it kom hjem and not var kommet hjem?

kom (simple past) suffices because før already gives the order.
var kommet hjem (past perfect) is possible if both events are anchored before another past reference point, but it often feels heavier than needed: Jeg havde allerede låst døren, før min mor var kommet hjem.

Which auxiliary do I use with komme and låse?

Why hjem and not hjemme?

Why is it døren and not den dør?

Danish marks definiteness with a suffix: dør → døren (“the door”).
den dør is a demonstrative (“that door”) or used with adjectives (double definiteness): den røde dør.

Why min mor and not moren? Can I say mor without min?

Possessives are used with kinship terms: min mor, din far. moren means “the mother” (not necessarily yours).
In family contexts, you can use the kin term as a name: Før mor kom hjem, ... This implies “my/our mother.”

Is låse the right verb here, not lukke?

How is the past participle låst formed?

From låse: present låser, preterite låste, past participle låst.
Regular pattern: many weak verbs form the participle with -t.

How does negation interact with før?

Ikke … før typically means “not until”: Jeg låste ikke døren, før min mor kom hjem.
Negating the før-clause itself is uncommon and often awkward; Danes usually place the negation in the main clause to express “not until.”

Any quick pronunciation tips for tricky words?