Formal:
* Adeus: This is the most formal way to say goodbye and is used in very formal situations like farewell speeches or when addressing someone of a much higher social standing.
* Até logo: This means "until later" and is slightly less formal than "adeus" but still appropriate for formal settings.
Informal:
* Tchau: This is the most common way to say goodbye in informal situations.
* Até mais: This means "see you later" and is another common informal phrase.
* Valeu: This means "thanks" or "cheers" and is used as a casual way to say goodbye, especially among friends.
Other options:
* Até breve: This means "see you soon" and can be used in both formal and informal situations.
* Até amanhã: This means "see you tomorrow" and is appropriate for situations where you'll see the person again the next day.
It's important to note that the appropriate goodbye will depend on the specific context and your relationship with the person. If you're unsure, it's always better to err on the side of formality.