Informal:
* O.K. (pronounced "oh kay") - This is the most common and casual way to say goodbye, similar to "see ya" or "later" in English.
* Bonjou (pronounced "bon-zhoo") - This literally translates to "good day" but is also used as a general farewell, similar to "goodbye" in English.
Formal:
* O revoir (pronounced "oh-re-vwar") - This is the most formal way to say goodbye, similar to "goodbye" in English.
* Bye bye (pronounced "bye bye") - This is a more formal way to say goodbye, but not as formal as "O revoir".
* Bon sò (pronounced "bon so") - This means "good luck" and is a more formal way to say goodbye, especially if you won't see the person for a long time.
More specific farewells:
* Bon nuit (pronounced "bon nwee") - "Good night"
* Bon apremidi (pronounced "bon ap-re-mee-dee") - "Good afternoon"
* Bon maten (pronounced "bon ma-ten") - "Good morning"
It's important to note that the formality of the goodbye will depend on the context and your relationship with the person you are saying goodbye to.