I dag lærer vi udtrykket “ikke bare ... men også”, som vi bruger, når vi vil lægge ekstra vægt på noget.

Because Danish has V2 word order in main clauses. That means the finite verb normally comes in the second position.

• Vi lærer udtrykket i dag = neutral order
• I dag lærer vi udtrykket = when I dag is moved to the front, the verb lærer must stay in second position, so vi comes after it

This is very common in Danish and is one of the first word-order patterns English speakers need to get used to.

Udtryk means expression or phrase.
Udtrykket means the expression.

The ending -et is the definite article attached to the noun, which is very common in Danish.

• et udtryk = an expression
• udtrykket = the expression

So in this sentence, Danish says we are learning the expression, not just an expression.

It works like English not only ... but also.

It is used to add emphasis and show that something is true in two ways, with the second part adding something extra.

Examples:

• Han er ikke bare klog, men også sjov.
  = He is not only smart, but also funny.

• Hun taler ikke bare dansk, men også svensk.
  = She speaks not only Danish, but also Swedish.

The structure can connect:

• adjectives
• nouns
• verbs
• whole clauses

The important idea is: first thing + and even more, second thing too.

They are very similar, and both can often be translated as not only.

• ikke bare ... men også
• ikke kun ... men også

In many situations, they are interchangeable.
However, ikke bare can sometimes sound a bit more emphatic or stylistically stronger, while ikke kun may sound slightly more neutral.

For a learner, it is perfectly useful to learn ikke bare ... men også as a fixed expression.

Here som means that / which and introduces a relative clause.

It refers back to udtrykket:

• udtrykket, som vi bruger
  = the expression that we use

So som connects the noun udtrykket with extra information about it.

In English, that is often optional:

• the expression (that) we use

In Danish, som is very common in this kind of sentence.

Because after som, Danish uses subordinate clause word order, which is different from main-clause word order.

In a subordinate clause, the subject usually comes before the verb:

• main clause: I dag lærer vi ...
• subordinate clause: som vi bruger

So:

• vi = subject
• bruger = verb

That is the normal order after som.

Here når means when.

It introduces another subordinate clause:

• når vi vil lægge ekstra vægt på noget
• when we want to place extra emphasis on something

In Danish, når is commonly used for:

• repeated situations
• general situations
• situations seen as expected or regular

In this sentence, it means something like when we want to do that in general.

Again, because når starts a subordinate clause.

In Danish subordinate clauses, the normal order is:

subject + verb

So:

• når vi vil ... = correct
• når vil vi ... = not correct here

Compare:

• main clause: Vi vil lægge ekstra vægt på noget.
• subordinate clause: når vi vil lægge ekstra vægt på noget

This difference between main-clause and subordinate-clause word order is very important in Danish.

Literally, it means something like to place extra weight on something.

But idiomatically, it means:

• to emphasize something
• to give something extra emphasis
• to stress something more strongly

So vægt is literally weight, but in this expression it means importance / emphasis.

This is a very natural Danish expression.

Because the expression is built with the preposition på.

The full phrase is:

• lægge vægt på noget
  = to emphasize something
  = to place importance on something

So på belongs to the expression, just like English often needs a preposition in certain fixed phrases.

Examples:

• Hun lægger vægt på detaljer.
  = She emphasizes details.

• Vi vil lægge ekstra vægt på udtale.
  = We want to place extra emphasis on pronunciation.

You should learn lægge vægt på as one unit.

The commas mark subordinate or descriptive parts of the sentence.

• I dag lærer vi udtrykket ..., som vi bruger, når vi vil ...

The comma before som marks the relative clause:

• som vi bruger

The comma before når is also standard in Danish comma style:

• når vi vil lægge ekstra vægt på noget

Danish uses commas more systematically around subordinate clauses than English often does, so English speakers may notice more commas than they expect.

It can be used with both.

With words or short phrases

• Han er ikke bare træt, men også sulten.
• Hun købte ikke bare brød, men også ost.

With verbs

• Han ikke bare læser dansk, men også skriver det.

With whole clauses

• Det er ikke bare dyrt, men det tager også lang tid.

When possible, Danish often likes parallel structure, just like English. That means the two parts should match each other clearly.

In natural speech, speakers often stress the contrast:

• ikke BARE ... men OGSÅ

That extra stress helps show the emphasis.

Also, in real conversation, Danish speakers may sometimes use related expressions such as:

• ikke kun ... men også
• både ... og if the meaning is more like both ... and rather than not only ... but also

So if you want strong emphasis, ikke bare ... men også is a very useful pattern.