Parabéns!

A common Brazilian pronunciation is roughly pah-rah-BENGS.

A few helpful notes:

• The final -éns is nasal because of em/ens in Portuguese. It is not a plain English -ens sound.
• The stress falls on the last syllable: pa-ra-BÉNS.
• The r in para is usually a light tapped sound in the middle of the word.

The accent in é shows that:

• the stressed syllable is béns
• the vowel is an open é sound

So the word is stressed as pa-ra-BÉNS, not PA-ra-bens or pa-RA-bens.

Because it is plural in form. Parabéns is historically related to the idea of offering congratulations, which is also plural in English.

That said, learners should mostly treat Parabéns! as a fixed expression meaning:

• Congratulations!
• Happy birthday! in the right context

You do not normally change it to a singular form.

Yes. Very often, Parabéns! alone is completely natural.

For example, people say it:

• on birthdays
• after someone passes an exam
• after a promotion
• after a wedding
• after any achievement

It works much like Congratulations! in English, and in birthday situations it can function like Happy birthday!

No. That is one of the most important things to know.

In Brazilian Portuguese, Parabéns! is used:

• for birthdays
• for accomplishments
• for milestones
• for celebrations in general

So if someone gets a new job, wins a contest, graduates, or has a baby, Parabéns! is appropriate.

Both can be used for birthdays, but they are not exactly the same.

• Parabéns! = Congratulations! and, in birthday contexts, also naturally works as Happy birthday!
• Feliz aniversário! = more literally Happy birthday!

In Brazil, Parabéns! is extremely common for birthdays. Many learners expect a direct equivalent of English Happy birthday, but Brazilians very often just say Parabéns!

Yes. Very common expansions include:

• Parabéns pra você! = Congratulations to you! / common birthday wording
• Meus parabéns! = My congratulations!
• Muitos parabéns! = Many congratulations!
• Parabéns pelo seu trabalho! = Congratulations on your work!
• Parabéns pelo aniversário! is possible, but for birthdays people usually just say Parabéns!

In everyday speech, simple Parabéns! is already very natural.

It works in both formal and informal situations.

You can say Parabéns! to:

• a friend
• a coworker
• a teacher
• a boss
• a family member

If you want to sound more formal or specific, you can add more words:

• Parabéns pela conquista.
• Parabéns pelo excelente trabalho.

But the basic word itself is neutral and widely usable.

Yes, but learners most often encounter Parabéns pra você, especially in the traditional Brazilian birthday song.

A quick note:

• pra is a very common spoken contraction of para a or just an informal reduced form related to para
• In everyday speech, pra você sounds very natural in Brazil

So Parabéns pra você is extremely familiar and common.

Absolutely. It is very common in:

• text messages
• social media comments
• cards
• emails
• chat messages

You may see things like:

• Parabéns!
• Parabéns!!!
• Parabéns with a missing accent is common in casual typing, but the correct spelling is Parabéns
• Parabéns, tudo de bom! = Congratulations/Happy birthday, all the best!

So yes, it is very natural both in speech and writing.