pallas_atalanta:

Here are some basic info regarding religion in South Africa.
Zion Christian 11.1%, Pentecostal/Charismatic 8.2%, Catholic 7.1%, Methodist 6.8%, Dutch Reformed 6.7%, Anglican 3.8%, other Christian 36%, Islam 1.5%, other 2.3%, unspecified 1.4%, none 15.1% (2001 census).

Having some information can help you formulate questions.
Africa in general has various religious influences. In the North, many Muslim influence (from visiting Missionaries in the past). In the South, however, Christianity is of many influence. That being said, a large group in South Africa are Caucasian, aside from popular belief that all of Africa is black.

Also, Many of the religions in Africa exhibit syncretism (fusion of religions). Local folklore and practices from indigenous religions were fused with the popular World religion. Including the common respect and belief in appeasing the ancestor’s and spirits. Some forms of religions in Africa are animistic (belief that all objects have a soul).

In turn you may want to ask.
Can you please describe the role of ancestors in your religion?
If their religion is Native African Religion. You can ask;
What is the most common form of sacrifice in native African religions?
What are some “rites of passage” in your religion? i.e. puberty rites. Is it for both male and female?
Do you believe in “saints” (as in Christianity) or in jinn spirits (in Muslim)? Name some of them please.
Is your religion monotheistic or polytheistic?

Hope this helps!