Swahili language
The exact number of Swahili speakers, be it native or second-language speakers, is unknown and a matter of debate. Various estimates have been put forward and they vary widely, from 50 million to over 100 million. Swahili serves as a national language of four nations: Tanzania, Kenya, Uganda, and the DRC. Shikomor, the official language in Comoros and also spoken in Mayotte (), is related to Swahili. Swahili is also one of the working languages of the African Union and officially recognised as a lingua franca of the East African Community. South Africa legalized the teaching of Swahili in South African schools as an optional subject beginning in 2020.
Hausa language
Non-native speakers of Hausa numbered more than 25 million and, in some areas, live close to native Hausa. It has replaced many other languages especially in the north-central and north-eastern part of Nigeria and continues to gain popularity in other parts of Africa as a result of Hausa movies and music which spread out throughout the region.