Learn Hardcore Norwegian: Barna blir mer selvstendige når de gjør leksene regelmessig. - The children become more independent when they do their homework regularly.

barn is a neuter noun with these forms:
- et barn = a child (singular, indefinite)
- barnet = the child (singular, definite)
- barn = children (plural, indefinite)
- barna = the children (plural, definite)
The sentence talks about a specific or known group of children, so it uses the definite plural barna.

What does blir do here? Why not er?

blir (from å bli) means “become,” expressing change or development.
er states a current state. Compare:
- Barna er selvstendige = The children are independent (state)
- Barna blir mer selvstendige = The children become more independent (change)

Why not vil bli for “will become”?

Norwegian often uses the present (blir) for general truths/habits and cause–effect statements.
vil bli is possible but emphasizes a prediction or intention. Here, blir sounds more like a general rule.

Why mer and not flere?

Why does selvstendige end in -e?

Predicate adjectives agree in number: with a plural subject (barna), add -e → selvstendige.
Predicate adjectives do not take the definite ending; they use the indefinite plural form after verbs like er/blir: Barna er/Blir selvstendige.

Could I say selvstendigere?

You’ll occasionally see selvstendigere, but the natural, standard comparative is periphrastic: mer selvstendig(e).
Prefer mer selvstendige with plural subjects.

Why use når and not da?

når = when/whenever for present/future and repeated or habitual situations.
da = when for a specific event in the past.
- Når de gjør leksene… (whenever/when they do their homework)
- Da de gjorde leksene… (when they did their homework — one past occasion)

Could I use hvis instead of når?

Yes: Hvis de gjør leksene regelmessig… = If they do their homework regularly…
når emphasizes time/whenever (often implying a general rule); hvis emphasizes a condition.

Why is it når de gjør and not når gjør de?

In subordinate clauses (introduced by når, hvis, fordi, etc.), the word order is Subject–Verb: når de gjør.
Når gjør de …? is only used in a direct question meaning “When do they …?”

Where would ikke go if I wanted to negate the clause?

In the subordinate clause: når de ikke gjør leksene … (Subject + ikke + Verb).
In a main clause: De gjør ikke leksene … (Verb in 2nd position, then ikke).

Why gjør (lekser/leksene) and not leser (leksene)?

The set phrase is å gjøre lekser = to do homework.
å lese is “to read/study,” used in contexts like å lese til eksamen (study for an exam), not for “doing homework” in general.

Why is it leksene (definite plural)? Can I say lekser or leksene sine?

All are possible, with nuance:
- gjør lekser = do homework (in general).
- gjør leksene = do the (assigned) homework; the set of tasks is understood as specific/known.
- gjør leksene sine = do their own homework (reflexive possessive; clarifies ownership by the subject).
In everyday speech, omitting sine is common when context makes the possessor obvious.

Is the punctuation right with no comma before når?

Yes. When the subordinate clause follows the main clause, you normally don’t put a comma before når: Barna blir … når de …
If you front the subordinate clause, add a comma after it: Når de gjør leksene regelmessig, blir barna mer selvstendige.

Why doesn’t the adverb have a -t: regelmessig, not regelmessigt?

Adjectives ending in -ig, -lig, or -sk do not take -t in the adverb form. The adverb is identical to the adjective: regelmessig, rolig, vanlig.

Can I move regelmessig earlier in the clause?

Yes. Both are fine:
- når de gjør leksene regelmessig
- når de regelmessig gjør leksene
The first is very common; the second slightly foregrounds the adverb. Both are idiomatic.