I agree that Angola is worth looking into but in terms of English being a lingua Franca as you call it i know people who have worked there and won't deny the fact that English speakers are not there in large numbers.
My type of thinking is what keep the naive, clueless sheep from the wolves. You don't kill wolves with sheep, you kill them with wolf hounds. Keep preaching about the greatness of the Arab civilization all while trying to pass it for a black civilization. I have a lot of South Sudanese friends in Australia (many will return to South sudan to position of power); they know about Arab cruelty and perversion. They know how Arabs have turned the Africans in Northern Sudan into African-hating Arabs.There is one Africa. I will leave this topic alone rather than fuel your divisive argument. Your type of thinking is why most Blacks from outside have a difficult time living and working in Africa.
The official language is Portuguese, although the national language is Bantu with the number of dialects spoken as varied as the Bantu sub-tribes. English speaking people might have a problem...since English is not their first language.
There is no single language spoken by Angolans known as Bantu. smh