Først når barna har spist omelett, får de is.

Here først når means only when or not until.

So the sentence does not simply mean when the children have eaten omelette, they get ice cream. It is stronger than that: it says that eating the omelette is a condition that must be fulfilled first.

A very natural English equivalent is:

• Only when the children have eaten omelette do they get ice cream.
• The children don’t get ice cream until they have eaten omelette.

Literally, først means first, and når means when, but together they often work like only when / not until.

Because Norwegian main clauses normally follow the V2 rule: the finite verb comes in the second position.

In this sentence, the whole opening clause Først når barna har spist omelett is placed first. After that, the finite verb of the main clause must come next:

• Først når barna har spist omelett, får de is.

So the order is:

1. fronted clause
2. finite verb: får
3. subject: de

If you started directly with the subject, then you would get normal subject-verb order:

• De får is først når barna har spist omelett.

So får de is not random inversion; it happens because something else has been placed first.

Har spist is the present perfect of spise (to eat).

• har = have/has
• spist = past participle of spise

It is used here because the eating must be completed before the children get the ice cream.

So the logic is:

1. the children have eaten the omelette
2. then they get ice cream

This is very similar to English:

• when the children have eaten...

It shows a completed action that comes before the next event.

Yes, it can be.

Norwegian often uses the present tense for:

• general rules
• routines
• near-future situations
• conditions

So får de is can mean something like:

• then they get ice cream
• then they will get ice cream

depending on context.

In this sentence, it often sounds like a rule or routine: once the children have finished the omelette, ice cream is allowed.

Because når is used for:

• something that happens whenever
• something in the present/future
• a general condition

Da is more often used for:

• a specific event in the past

So here, når is right because the sentence expresses a condition or rule, not a one-time past event.

Compare:

• Når barna har spist omelett, får de is.
  = When/once the children have eaten omelette, they get ice cream.

• Da barna hadde spist omelett, fikk de is.
  = When the children had eaten omelette, they got ice cream.

Barna is the definite plural form of barn (child / children).

The forms are:

• et barn = a child
• barnet = the child
• barn = children
• barna = the children

So in this sentence, barna means the children.

This can feel unusual to English speakers because Norwegian usually puts definiteness at the end of the noun instead of using a separate word like the.

Because Norwegian often allows a bare noun after verbs like spise when talking about food in a general way.

So spist omelett is natural and means something like:

• eaten omelette
• eaten an omelette

The focus is on the type of food, not on counting one individual item.

If you want to stress one omelette / a specific portion, you can also say:

• har spist en omelett

That would sound a bit more countable and specific.

So:

• spist omelett = general food idea
• spist en omelett = more clearly eaten an omelette

For the same general reason: is here is being used as an uncounted food noun, meaning ice cream in general.

So:

• får is = get ice cream

If you say:

• får en is

that usually means:

• get an ice cream
• get one ice cream / one serving / one ice cream item

So the sentence as written is talking about ice cream as a treat in general, not emphasizing the number of portions.

Because the sentence begins with a subordinate clause, and in Norwegian that is commonly separated from the main clause with a comma.

The structure is:

• Først når barna har spist omelett = subordinate clause
• får de is = main clause

So the comma marks the boundary between those two parts.

This is very common in Norwegian writing:

• Når jeg kommer hjem, lager jeg middag.
• Hvis det regner, blir vi inne.

Yes. That is also a natural sentence, and it expresses basically the same idea.

The difference is mainly focus:

• Først når barna har spist omelett, får de is.
  This strongly emphasizes the condition. It feels close to Not until...

• Barna får først is når de har spist omelett.
  This is a bit more neutral and straightforward.

So both are correct, but the original sentence gives extra emphasis to the only after this happens idea.

Because once barna has been introduced, Norwegian can refer back to them with the pronoun de (they).

So:

• barna = the children
• de = they

This avoids repeating the noun:

• Først når barna har spist omelett, får de is.

A version with repetition would be grammatical but less natural:

• Først når barna har spist omelett, får barna is.

Using de sounds smoother and more natural.