SA has 2 main languages Zulu and Xhosa. They call it 2 but they can communicate with each other.In nig context it not 2 diff lang but accent.The nation has 11 languages .The Zulu have the highest population followed by the Xhosa.
Some of them look like ibo,some like hausa while others have the look of Yoruba. they used the word 'sisi' to address a females while it is an insult to call your mother's agemate sisi, just the same way it is used in yoruba. Dog is called Nja while Yoruba call it aja. When unmodernised yorubas we talk they used the exclamation 'awu'. It is used the same way here in the same context.