Informal:
* Tchau: This is the most common and informal way to say "bye".
* Até logo: This means "see you soon" and is another common informal option.
* Valeu: This literally means "worth it" and is used as a way of saying "thanks" or "bye" in a casual setting.
Formal:
* Adeus: This is the most formal way to say "goodbye".
* Até breve: This means "see you soon" and is a more formal option than "até logo".
Other options:
* Até mais: This means "see you later" and can be used in both formal and informal settings.
* Até: This is a short form of "até logo" or "até breve" and is used to say "bye" in a casual setting.
The best way to choose the right translation for "bye" depends on the context and your relationship with the person you are speaking to.