Learn Hardcore Norwegian: Barna koser seg på verandaen når vinden er stille. - The children enjoy themselves on the veranda when the wind is calm.

å kose seg means “to enjoy oneself, have a cozy/nice time” and is reflexive, so you must use the reflexive pronoun.
Without seg, å kose typically means “to cuddle/pet” someone/something: Barna koser katten.
For third-person plural (the children), the reflexive pronoun is seg: barna koser seg.

Can I replace seg with dem, or drop it?

No. dem is a non-reflexive object pronoun (“them”), which would change the meaning (the children cuddle them).
To express “enjoy themselves,” you must keep the reflexive seg. Dropping it changes the verb’s meaning.

Could I use hygger seg or nyter instead of koser seg?

å hygge seg is a close synonym and perfectly natural.
å nyte usually takes a direct object or an infinitive: Barna nyter sola / Barna nyter å være på verandaen. Using nyter with no object is odd.
kose seg is the most colloquial, everyday choice for “having a cozy, pleasant time.”

What’s the word order with the når-clause? Why not Når er vinden stille here?

In a subordinate clause introduced by når, the order is Subject–Verb: når vinden er stille.
Når er vinden stille? is a question (interrogative inversion).
If you front the når-clause, remember main-clause V2: Når vinden er stille, koser barna seg på verandaen.

Why is it barna and not barnene?

barn is a neuter noun with an irregular plural:
- Indefinite singular: et barn
- Indefinite plural: barn
- Definite plural: barna (not barnene)

Why på verandaen and not i verandaen?

For open, surface-like places, Norwegian uses på: på verandaen, på balkongen, på terrassen.
i is used for enclosed spaces: i stua, i huset.
So location on a veranda/balcony/terrace is naturally på.

Why are the nouns definite (verandaen, vinden)? Could I use the indefinite?

Norwegian often uses the definite form for contextually known things (the home veranda, the local wind).
Indefinite suggests a random/unspecified one: på en veranda (on some veranda) feels different; når en vind er stille is not idiomatic.
Generic weather can also be expressed impersonally: når det er vindstille.

Is vinden er stille the most natural? What are alternatives?

It’s fine, but very common alternatives are:
- når det er vindstille (there’s no wind)
- når det ikke blåser (when it isn’t windy)
Nuance: blir stille = becomes calm (change), er stille = is calm (state).

What’s the difference between stille and rolig here?

stille refers to quietness/lack of movement; with wind it means calm.
rolig means calm/tranquil, often about people or general mood. Vinden er rolig is understandable but less idiomatic than vinden er stille or det er vindstille.

Can I move på verandaen to the front?

Yes. Fronting an adverbial triggers inversion (V2) in the main clause:
- På verandaen koser barna seg når vinden er stille.
In the original order, the finite verb still sits in second position: Barna koser seg ...

Any pronunciation tips for tricky parts?

å in når is like the vowel in English “law.”
o in koser is long, like “oo” in “food.”
In many accents, rn in barna is a single retroflex sound; you’ll hear something like bahr-na.
Typical stress: BArna, KOser, veRANdaen, STILle.

Veranda vs balcony vs terrace in Norwegian?

veranda: porch-like area attached to a house, often roofed.
balkong: projects from an upper floor.
terrasse: larger deck or ground-level patio. Usage overlaps in everyday speech.

Should there be a comma before når?

No comma is needed when the når-clause follows the main clause: Barna koser seg … når vinden er stille.
If you place the når-clause first, add a comma after it: Når vinden er stille, koser barna seg …

Where does seg go in the sentence?