Min søster siger, at hun ikke bliver rigtig vågen, før hun har drukket kaffe og åbnet vinduet.

Because søster is a common-gender noun in Danish.

• min = for singular common-gender nouns
• mit = for singular neuter nouns
• mine = for plurals

So:

• min søster = my sister
• mit vindue = my window
• mine søstre = my sisters

This comma marks the start of a subordinate clause: at hun ikke bliver rigtig vågen ...

In Danish, there are two accepted comma systems:

• with start comma: Min søster siger, at ...
• without start comma: Min søster siger at ...

So the comma here is correct, but in modern Danish you may also see the sentence written without it.

Usually, yes in standard written Danish.

Here, at means that and introduces the clause hun ikke bliver rigtig vågen ...

• Min søster siger, at ... = standard and very common
• Min søster siger ... without at can happen in informal speech and casual writing, but it is less formal and less neutral

So for learners, it is safest to keep at.

Because this is a subordinate clause, and Danish word order changes in subordinate clauses.

After at, the usual order is:

subject + sentence adverb + finite verb

So:

• hun ikke bliver

not:

• hun bliver ikke

Compare:

• Main clause: Hun bliver ikke rigtig vågen
• Subordinate clause: at hun ikke bliver rigtig vågen

This is one of the most important Danish word-order patterns to learn.

Because bliver suggests becoming or getting into a state, not just already being in that state.

So:

• er vågen = is awake
• bliver vågen = becomes / gets awake

In this sentence, the idea is that she does not really wake up properly until after certain things happen. So bliver fits better than er.

English often expresses this more naturally as doesn’t really wake up or doesn’t really get properly awake.

Here rigtig means something like really, properly, or fully.

So rigtig vågen means:

• really awake
• properly awake
• fully awake

It does not mean correct awake here. The word rigtig can mean correct/right in other contexts, but in this sentence it is an intensifier.

Literally, før means before.

But in a sentence like this, English often uses until more naturally:

• She doesn’t really wake up until she has had coffee...

So the Danish structure is literally not ... before, but the most natural English meaning is often not ... until.

That is very common with negative statements.

Because Danish is emphasizing that these actions are completed before she becomes properly awake.

• har drukket kaffe = has drunk / has had coffee
• har åbnet vinduet = has opened the window

The idea is:

She is not really awake before these things have happened.

So the perfect form har + past participle highlights completion.

Because both verbs share the same auxiliary verb.

So:

• har drukket kaffe og åbnet vinduet

means:

• has drunk coffee and opened the window

Danish does not need to repeat har when the same subject and the same auxiliary apply to both verbs.

You could repeat it for clarity in some contexts, but normally you do not.

Because drikke is an irregular verb.

Its main forms are:

• infinitive: drikke
• present: drikker
• past: drak
• past participle: drukket

So after har, you need the past participle:

• har drukket

This is just one of the irregular verb patterns that has to be learned.

Because kaffe is being used as an uncountable mass noun here, just like coffee in English.

So:

• drikke kaffe = drink coffee

You do not need en here.

If you wanted to talk about a coffee as one serving, that is different and depends on context, but in this sentence it simply means coffee in general.

Because vinduet is the definite form, meaning the window.

• et vindue = a window
• vinduet = the window

Danish often adds definiteness as an ending instead of using a separate word like the.

So:

• åbnet vinduet = opened the window

This suggests a specific window, probably one that is understood from the situation.

Because the adjective matches the subject.

Here the subject is hun, which refers to a singular common-gender person, so the adjective stays in its basic form:

• hun er vågen
• hun bliver vågen

You would use -t with a singular neuter noun:

• barnet er vågent = the child is awake

So vågen is correct with hun.