Formal:
* Adeus: This is the most formal way to say goodbye. It is used in situations where you want to be polite and respectful.
* Até logo: This means "see you soon" and is also a formal way to say goodbye. It's appropriate for situations where you expect to see the person again soon.
* Com licença: This literally means "with permission," but it's used as a polite way to excuse yourself from a conversation.
Informal:
* Tchau: This is the most common way to say goodbye in informal settings. It's similar to "bye" in English.
* Até mais: This means "see you later" and is used in informal situations when you don't know exactly when you'll see the person again.
* Até já: This means "see you soon" and is used in informal situations when you expect to see the person again within a short period of time.
* Valeu: This means "thanks" or "cheers" and is used as a way to say goodbye among friends.
More specific options:
* Boa noite: This means "good night" and is used when saying goodbye in the evening or at night.
* Bom dia: This means "good morning" and is used when saying goodbye in the morning.
* Boa tarde: This means "good afternoon" and is used when saying goodbye in the afternoon.
The best way to choose the right phrase depends on the specific situation and your relationship with the person you are saying goodbye to.