Hun plejer ikke at klage over vejret, men i november gør hun det især, når vinden er kold.

Plejer means usually, tends to, or is in the habit of.

The pattern is:

• pleje at + infinitive

So:

• Hun plejer at klage = She usually complains
• Hun plejer ikke at klage = She does not usually complain

It describes a habit or something that normally happens.

Because pleje is normally followed by at + infinitive.

Here:

• at klage = to complain

So the full structure is:

• hun plejer ikke at klage

This is very common in Danish. English often drops to in some structures, but Danish keeps at here.

Because klage over is the normal expression for complain about.

So:

• klage over noget = complain about something

Examples:

• Han klager over støjen = He complains about the noise
• De klager over maden = They complain about the food

For English speakers, the important thing is that about is often over after klage.

Vejr means weather, while vejret means the weather.

In Danish, you very often use the definite form when talking about weather in a general sense:

• klage over vejret = complain about the weather

So this is the natural form here. English also usually says the weather, so the match is quite close.

Here gør ... det stands in for the earlier action instead of repeating it.

The earlier action is:

• at klage over vejret

So:

• i november gør hun det især

means roughly:

• in November she does that especially
• in more natural English: she especially does so in November

Danish often uses gøre det this way to avoid repeating the whole verb phrase.

Det does not refer to vejret.

It refers to the whole action:

• at klage over vejret

So you can think of det as meaning that, where that = complaining about the weather.

Because Danish main clauses normally follow the verb-second rule.

That means the finite verb comes in the second position, even if something other than the subject comes first.

Here the sentence begins with:

• i november

So the verb must come next:

• I november gør hun det især

Then the subject comes after the verb:

• gør hun

This inversion is very normal in Danish.

Yes, you could.

Compare:

• Hun gør det især i november
• I november gør hun det især

Both are grammatical. The difference is mainly focus.

• Hun gør det især i november = more neutral
• I november gør hun det især = puts extra emphasis on in November

So the version in the sentence highlights the time.

Især means especially or particularly.

In this sentence, it emphasizes that November is the time when she does this most.

So:

• i november gør hun det især = she especially does it in November

Its exact position can vary a little, but the placement here is natural and idiomatic.

Because når is used for when / whenever, especially for things that happen regularly or typically.

Here the sentence describes a repeated pattern:

• she complains especially when the wind is cold

So når fits well.

By contrast:

• hvis = if

That would sound more conditional or uncertain.

A simple contrast:

• Når vinden er kold, klager hun = When the wind is cold, she complains
• Hvis vinden bliver kold, klager hun = If the wind gets cold, she will complain

Because når introduces a subordinate clause, and subordinate clauses do not use the same inversion pattern as main clauses.

So the normal order is:

• vinden er kold = the wind is cold

After når, that order stays the same:

• når vinden er kold

This is an important difference:

• Main clause: I november gør hun det især
• Subordinate clause: når vinden er kold

Because in Danish, months are normally not capitalized.

So Danish writes:

• november
• mandag
• dansk

not:

• November
• Mandag
• Dansk

unless the word starts the sentence. This is different from English.

The comma before men is straightforward: it separates two main clauses.

• Hun plejer ikke at klage over vejret, men ...

The comma before når marks the start of a subordinate clause:

• ..., når vinden er kold

You should know that in Danish, you may also see this written without that second comma, depending on the comma style being used:

• ..., især når vinden er kold

So the first comma is standard, and the second one can vary by comma convention.