Prietenii fac un pariu.

Prietenii means the friends.

In Romanian, the definite article is usually attached to the end of the noun instead of being a separate word like English the.

• prieteni = friends
• prietenii = the friends

So the sentence uses a definite subject: the friends.

That ending combines two things:

• -i marks the masculine plural
• the second -i is the definite article for this form

So:

• prieten = friend
• prieteni = friends
• prietenii = the friends

This double i is very common in Romanian masculine plural definite nouns.

The two is are not just decorative; they affect pronunciation.

A learner-friendly approximation is:

• prietenii ≈ pree-ye-NEE-ee

The final part is lighter than in English, but both i sounds matter. In careful speech, the ending is distinct from prieteni.

Very roughly:

• prieteni = pree-YEH-teny
• prietenii = pree-ye-TE-nee-ee / pree-ye-TEN-y-ee depending on speed and accent

The key point is that prieteni and prietenii are different both in grammar and pronunciation.

Fac is the 3rd person plural form of the verb a face, which usually means to do or to make.

Since prietenii = the friends is plural, the verb must also be plural:

• el/ea face = he/she does, makes
• ei/ele fac = they do, make

So:

• Prietenii fac... = The friends make/do...

In this sentence, a face is being used in a common expression: a face un pariu.

Romanian often expresses this idea with the phrase a face un pariu, literally to make a bet.

That is very similar to English, since English also says make a bet.

You may also encounter related expressions, such as:

• a paria = to bet
• a pune pariu = to bet / to make a bet

But a face un pariu is a perfectly natural structure.

Un is the indefinite article, meaning a or an.

So:

• un pariu = a bet

Romanian has gendered forms for the indefinite article:

• un for masculine/neuter singular nouns
• o for feminine singular nouns

Since pariu is treated as a masculine/neuter-type noun in the singular, it takes un.

Pariu means bet and is a neuter noun in Romanian.

Romanian neuter nouns behave:

• like masculine in the singular
• like feminine in the plural

That is why you get:

• un pariu = a bet
• două pariuri = two bets

So in this sentence, the singular pariu takes un.

Romanian often leaves out subject pronouns when the verb form already makes the subject clear.

Because fac already means they do/make, you do not need ei (they).

So Romanian prefers:

• Prietenii fac un pariu.

rather than:

• Ei fac un pariu.

Of course, ei can be added for emphasis or contrast, but it is not necessary.

The basic word order is natural and neutral:

• Prietenii fac un pariu.

Romanian word order is fairly flexible, though, because endings often show grammatical roles clearly.

Other orders may be possible for emphasis, but this version is the most straightforward and neutral for a learner.

So this sentence is a good example of standard subject + verb + object order.

In standard Romanian, prietenii specifically means the friends.

If you want just friends in a general or indefinite sense, you normally use:

• prieteni

So the contrast is:

• Prieteni fac un pariu. = Friends make a bet / Some friends make a bet
• Prietenii fac un pariu. = The friends make a bet

The definite form is important.

Because the sentence means the friends make a bet, not the friends make the bet.

So:

• prietenii is definite: the friends
• un pariu is indefinite: a bet

If you made pariu definite, it would become pariul:

• Prietenii fac pariul. = The friends make/do the bet

But that sounds less natural in most contexts, because a face un pariu is the normal expression.

It is neutral and standard. Nothing in it is especially formal or especially casual.

A Romanian speaker could use it in everyday conversation, in teaching examples, or in simple written language.

So it is a very useful beginner sentence because it contains normal, common grammar:

• a definite plural noun
• a common verb form
• an indefinite object
• standard word order