När barnen har somnat ska vi sitta på balkongen och dricka te.

När means when and introduces a time clause: När barnen har somnat = When the children have fallen asleep.

A learner may confuse när with om. In Swedish:

• när is used for when in real/expected situations
• om is used for if

So here, the speaker expects the children to fall asleep, so när is the natural choice.

Barn means children in general, while barnen means the children.

So:

• barn = children
• barnen = the children

The ending -en is the definite plural ending here. Swedish often puts definiteness on the noun itself instead of using a separate word like the.

Yes, har somnat is formally the present perfect: have fallen asleep.

Swedish often uses the present perfect in a time clause referring to the future when one action must be completed before another happens.

So:

• När barnen har somnat literally: When the children have fallen asleep
• Then the main action happens: ska vi sitta ...

English does something similar:

• When the children have fallen asleep, we’ll sit on the balcony...

In more everyday English, people might also say When the children are asleep, but the Swedish sentence specifically focuses on the moment after they have fallen asleep.

This is a very common question.

• somna = to fall asleep
• sova = to sleep

So har somnat does not mean have slept. It means have fallen asleep.

Compare:

• Barnen somnar. = The children are falling asleep / fall asleep.
• Barnen sover. = The children are sleeping.

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

The sentence begins with a subordinate clause:

När barnen har somnat

After that, the main clause begins, and the finite verb must come next:

ska vi sitta på balkongen och dricka te

So the order is:

1. fronted element: När barnen har somnat
2. finite verb: ska
3. subject: vi

If you started directly with the main clause, you would say:

• Vi ska sitta på balkongen och dricka te.

But once the time clause comes first, inversion happens:

• När barnen har somnat ska vi ...

Because this is a subordinate clause, and Swedish subordinate clauses do not use the same inversion pattern as main clauses.

So after när, the normal order is:

• subject: barnen
• finite verb: har
• supine/main verb form: somnat

That gives:

När barnen har somnat

If you said När har barnen somnat?, that would sound like a direct question: When have the children fallen asleep?

Here ska expresses a future plan or intention. In natural English, it is often translated as:

• will
• are going to
• sometimes shall in more formal or older-style English

So ska vi sitta på balkongen och dricka te means something like:

• we’ll sit on the balcony and drink tea
• we’re going to sit on the balcony and drink tea

In everyday Swedish, ska is one of the most common ways to talk about the future.

Because after the modal verb ska, Swedish normally uses the infinitive without att.

So:

• ska sitta
• ska dricka

not:

• ska att sitta
• ska att dricka

Also, since sitta and dricka are joined by och, the second infinitive also appears without att:

• ska vi sitta på balkongen och dricka te

Swedish often uses posture verbs where English uses a more general verb.

• sitta = sit
• stå = stand
• ligga = lie
• vara = be

So sitta på balkongen is very natural Swedish and means sit on the balcony. English also says this, so it matches nicely here.

In other contexts, Swedish may use these posture verbs more often than English does.

Because på is the normal preposition for being on a balcony.

• på balkongen = on the balcony

Swedish and English often match here. A balcony is thought of as a surface/space you are on, not something you are inside.

So:

• på balkongen = correct
• i balkongen = not natural here

Because te is being used as an uncountable noun, like tea in English.

So:

• dricka te = drink tea

Just like in English, you usually do not need an article with a drink or substance in a general sense.

If you wanted to be more specific, you could add something:

• dricka ett te is not the normal way to say drink a tea in this context
• more natural would be something like dricka en kopp te = drink a cup of tea

Sometimes yes, but the nuance changes a little.

• ska often suggests intention, plan, or what one is going to do
• kommer att often sounds more like a neutral future prediction

So:

• När barnen har somnat ska vi sitta på balkongen och dricka te. = after the children fall asleep, that is our plan

A version with kommer att is possible in some contexts, but ska sounds more natural for a planned action by the speaker and another person.

Yes. The single ska covers both infinitives:

• sitta
• dricka

So the structure is basically:

• ska vi [sitta på balkongen] och [dricka te]

You do not need to repeat ska:

• natural: ska vi sitta på balkongen och dricka te
• possible but heavier: ska vi sitta på balkongen och ska vi dricka te — this would sound wrong here

Swedish often uses one modal verb for two coordinated infinitives like this.