Legally you are able to teach and work in Korea.
I know a guy from Cameroon who speaks two-three languages. Anyway, what you have to be aware of is that there is some prejudice out there in South Korea. Some Africans have been left at the airport, so to prevent this from happening, you must send your photo. It's their loss if they don't want you based on color. But make sure it's not your loss of a round trip fare if you fail to provide photos.A lot of schools want white faces, which is not very PC in the western nations. Even western born, ethnic Koreans have a hard job getting work. SO TRY! If you do end up going, visit Itaewon on the light brown subway. You will find some fellow country men and women there.

Jo