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
Hausa (; "Yaren Hausa" or "Harshen Hausa") is the Chadic language (a branch of the Afroasiatic language family) with the largest number of speakers, spoken as a first language by some 44 million people, and as a second language by another 20 million. The total number of Hausa speakers is estimated at 63 million, according to Ethnologue.
The ancestral language of the Hausa people, one of the largest ethnic groups in Central Africa, Hausa is mostly spoken throughout southern Niger and northern Nigeria. It has developed into a lingua franca across much of Western Africa for purposes of trade.