Før vi kjører, sjekker jeg at både forsetet og baksetet er ryddige, og at alle har på seg bilbelte.

Før means before and introduces a subordinate clause.

So:

• Før vi kjører = before we drive / before we leave

In Norwegian subordinate clauses, the subject usually comes before the verb in normal order:

• vi kjører = we drive / we leave

So Før vi kjører is the correct structure.
Før kjører vi would not work here.

Because this is a full clause with a subject and a present-tense verb:

• vi kjører = we drive / we are driving / we leave

Norwegian often uses the present tense in places where English might also say before we leave. The infinitive å kjøre would only be used in structures like:

• før vi skal kjøre
• før å kjøre is not correct here

So kjører is the finite verb needed for the clause.

This is because Norwegian follows the V2 rule in main clauses: the finite verb usually comes in the second position.

The first element in the main clause is the subordinate clause:

• Før vi kjører

Since that whole clause comes first, the verb of the main clause must come next:

• sjekker

Then comes the subject:

• jeg

So:

• Før vi kjører, sjekker jeg ...

If the sentence started directly with the subject, then you would say:

• Jeg sjekker at ...

Here at means that and introduces content clauses after sjekker.

The speaker is checking that something is true:

• sjekker jeg at både forsetet og baksetet er ryddige
• og at alle har på seg bilbelte

So the sentence contains two at-clauses:

1. that both the front seat and the back seat are tidy
2. that everyone is wearing a seat belt

In English, that is often optional, but in Norwegian at is commonly used in this kind of sentence.

Because the sentence joins two parallel subordinate clauses:

• at både forsetet og baksetet er ryddige
• og at alle har på seg bilbelte

Repeating at makes the structure clear and natural. It is similar to English:

• I check that the front and back seats are tidy, and that everyone is wearing a seat belt.

Sometimes Norwegian can omit a repeated conjunction in other contexts, but here repeating at is very normal and clear.

Både ... og ... means both ... and ....

In the sentence:

• både forsetet og baksetet = both the front seat and the back seat

This is a fixed pairing:

• både kaffe og te = both coffee and tea
• både han og jeg = both he and I

So if you use både, you normally also use og later in the phrase.

Because Norwegian often forms compound nouns as a single word.

• for = front
• sete = seat
• forsete(t) = front seat
• bak = back
• baksete(t) = back seat

The -et ending here is the definite singular ending for a neuter noun:

• et forsete = a front seat

• forsetet = the front seat

• et baksete = a back seat
• baksetet = the back seat

This is very common in Norwegian. English often writes these as separate words, but Norwegian usually combines them.

Because the adjective agrees with the noun phrase it describes.

The subject here is:

• både forsetet og baksetet

That refers to two things, so the adjective is plural:

• ryddige = tidy (plural)

Compare:

• Forsetet er ryddig = The front seat is tidy
• Baksetet er ryddig = The back seat is tidy
• Forsetet og baksetet er ryddige = The front seat and the back seat are tidy

So even though each noun is singular, together they form a plural idea.

Ha på seg is an expression meaning to be wearing.

So:

• ha på seg bilbelte = to have a seat belt on / to be wearing a seat belt

This is a very common Norwegian structure for clothing and things worn on the body:

• Hun har på seg jakke = She is wearing a jacket
• Han har på seg briller = He is wearing glasses

The parts work together:

• ha = have
• på = on
• seg = oneself

You should learn ha på seg as a unit.

Because Norwegian often uses verb + particle + reflexive pronoun combinations where English uses a single verb.

• har på seg literally looks like has on oneself
• but the natural meaning is is wearing

This is just how Norwegian expresses the idea. Many learners find it useful to memorize the whole phrase:

• å ha på seg = to wear / to have on

Here bilbelte is an indefinite noun used in a general sense.

• bilbelte = seat belt / a seat belt

In Norwegian, after expressions like ha på seg, clothing and similar items are often left indefinite:

• har på seg jakke
• har på seg hatt
• har på seg bilbelte

You could say et bilbelte in some contexts, but here bare bilbelte sounds natural and idiomatic.

Also, bilbelte is another compound noun:

• bil = car
• belte = belt
• bilbelte = seat belt

Alle har på seg bilbelte is the most natural phrasing here.

• alle = everyone
• har på seg = is wearing
• bilbelte = seat belt

Other word orders may be possible in special contexts, but this one is standard and neutral.

As for et bilbelte, it is grammatically possible, but less idiomatic in this sentence. Norwegian often uses the bare noun after ha på seg.

Grammatically, alle refers to more than one person in meaning, but it takes the verb form har, which is the same for singular and plural in the present tense anyway.

Norwegian present-tense verbs do not change according to person or number:

• jeg har
• du har
• han har
• vi har
• alle har

So you do not see singular/plural agreement on the verb the way you might in some other languages.

The comma separates the introductory subordinate clause from the main clause:

• Før vi kjører, sjekker jeg ...

This kind of comma is very common and helps readability.

Even if comma rules can vary a bit by style, writing a comma here is normal and clear.

Not exactly. Ryddig/ryddige usually means tidy, neat, or in order, rather than physically clean.

So here it suggests that the seats are not cluttered or messy.

Compare:

• ryddig = tidy, organized
• ren = clean

A seat can be ryddig without being especially ren, and vice versa.

Because Norwegian commonly uses the present tense for near-future or scheduled actions, especially when the timing is clear from context.

So:

• Før vi kjører literally uses present tense
• but in English the natural meaning may be Before we leave or Before we drive off

This is normal in Norwegian and not unusual. The time relationship is already clear from før.