Dansul începe acum.

Because -ul is the Romanian definite article attached to the end of the noun.

• dans = dance
• dansul = the dance

Unlike English, Romanian usually puts the at the end of the noun instead of before it.

So:

• Dans începe acum would sound wrong here
• Dansul începe acum = The dance begins now

Începe means begins / starts.

It is the 3rd person singular present tense form of the verb a începe = to begin / to start.

In this sentence, the subject is dansul (the dance), which is singular, so Romanian uses începe:

• eu încep = I begin
• tu începi = you begin
• el/ea începe = he/she/it begins
• dansul începe = the dance begins

Romanian usually expresses the by adding it to the end of the noun. This is one of the big differences from English.

For masculine/neuter nouns in the singular, a common definite ending is -ul.

So here:

• dans = dance
• dansul = the dance

This is completely normal Romanian structure.

Yes. dans is a masculine noun in Romanian.

That matters because Romanian nouns have gender, and the form of the definite article depends on gender and number.

For example:

• masculine singular: often -ul
• feminine singular: often -a
• plural forms: different again

So dansul is the masculine singular definite form.

Yes, Romanian word order is fairly flexible.

Dansul începe acum is a neutral, natural way to say it:

• Dansul = the subject
• începe = the verb
• acum = now

But you could also hear:

• Acum începe dansul. = Now the dance begins.
• Începe acum dansul. = less neutral, more emphasis-driven

The original sentence is the most straightforward way to say it.

Acum means now.

It can mean:

• now in a general sense
• right now depending on context

In this sentence, it simply tells you when the action happens:

• Dansul începe acum. = The dance starts now.

A helpful approximation is:

DAHN-sool in-CHE-peh ah-KOOM

A bit more detail:

• dansul → DAHN-sul
• începe → in-CHE-pe
• acum → a-KUM

A few useful pronunciation notes:

• ce in începe sounds like che in check
• ă does not appear here, but â/î in Romanian is a special central vowel; in începe, the first în- contains î
• the stress is roughly:
  • DANsul
  • înCEpe
  • aCUM

Yes. In many contexts, a începe can mean both to begin and to start.

So this sentence could be translated as either:

• The dance begins now.
• The dance starts now.

Both are natural.

In this sentence, dansul clearly means the dance.

A learner might confuse it with dânsul, which is a different word.
These are not the same:

• dansul = the dance
• dânsul = a polite/literary form meaning he / him

The circumflex matters:

• dansul → noun
• dânsul → pronoun

So here, with the meaning already given and the sentence context, it is definitely the dance.

No. Romanian does not need a separate subject pronoun when the subject noun is already stated.

The subject is already present:

• Dansul = the dance

So începe is enough as the verb form, and no extra pronoun is needed.

Romanian often leaves out pronouns unless they are needed for emphasis or clarity.

Sometimes, depending on context, yes.

dans usually means dance, but in English the best translation may vary:

• The dance starts now.
• The dancing starts now.

If the situation is about a formal event, The dance starts now is likely best.
If the focus is on the activity itself, The dancing starts now could also work.

But the direct Romanian form here is most naturally understood as The dance starts now.