Bytterunden begynner nå.

Because Norwegian normally writes compound nouns as a single word.

Bytterunden is made from:

• bytte = swap / exchange / trade
• runde = round

So bytterunde means something like swap round, exchange round, or trading round, depending on context.

This is very common in Norwegian. Where English often uses two words, Norwegian often uses one compound word instead.

The ending -en is the definite article attached to the noun.

• en runde = a round
• runden = the round

So:

• bytterunde = swap round / exchange round
• bytterunden = the swap round / the exchange round

Norwegian usually puts the definite article at the end of the noun instead of using a separate word like the.

Begynner is the present tense of å begynne, which means to begin.

Examples:

• jeg begynner = I begin / I am beginning
• du begynner = you begin
• den begynner = it begins
• bytterunden begynner = the swap round begins

A useful thing for learners: in Norwegian, the present tense form is the same for all persons. You do not change it the way English changes begin to begins.

Because Norwegian often uses the simple present where English might use either the simple present or the present progressive.

So begynner nå can correspond to:

• begins now
• is beginning now

Norwegian does not usually need a separate verb like is for this meaning.

Nå means now, and putting it at the end is very natural in Norwegian.

So:

• Bytterunden begynner nå. = The swap round begins now.

The sentence follows normal Norwegian main-clause word order:

• Bytterunden = subject
• begynner = verb
• nå = time adverb

You can move nå for emphasis in some contexts, but the version here is the most neutral and straightforward.

Because Norwegian usually expresses definiteness by adding an ending to the noun.

Compare:

• en bytterunde = a swap round
• bytterunden = the swap round

So English uses a separate article, but Norwegian usually builds definiteness into the noun itself.

Yes, in many contexts starter could work.

• begynner = begins
• starter = starts

Both are common, but begynner can sound slightly more neutral or formal in some situations, while starter can feel a bit more direct. In many real-life contexts, either would be understood.

So Bytterunden starter nå is also possible.

In a main-clause yes/no question, Norwegian usually puts the verb before the subject.

Statement:

• Bytterunden begynner nå.

Question:

• Begynner bytterunden nå?

This is a very important pattern in Norwegian: verb first, subject second in yes/no questions.

A rough guide is:

BYT-te-run-den

A few pronunciation notes:

• y in bytte is a front rounded vowel that English does not really have.
• The tt makes the preceding vowel short.
• Stress is mainly on the first part: BYT-terunden.

If you are learning Bokmål, remember that spelling does not always tell you everything about pronunciation, so listening to native audio is very helpful here.

This sentence is standard Bokmål.

In Nynorsk, you would more likely see:

• Byterunden byrjar no.

Differences:

• begynner in Bokmål often corresponds to byrjar in Nynorsk
• nå in Bokmål is often no in Nynorsk

So the original sentence is clearly natural Bokmål.