Man, you need an African education. English is the official language of virtually every former British colony, including (in Africa) Nigeria, Ghana, Sierra Leone, Zambia, Zimbabwe, Malawi, Tanzania, Guinea, and, yes, Kenya. English is the "default" language because each of these countries has many, many tribal languages and they needed to pick a "neutral" language. For bonus points, what country has more English speakers and readers than any other country? --the answer is India, which has twice as many English speakers as the United States, and 11 times as many as England..
You are correct. I travel to India frequently. I am often used as the “interpreter” amongst Indians and their various dialects, but English is the only common language.
“Lingua franca”