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.
Wichí
The total number of speakers can only be estimated; no reliable figures exist. Comparing several sources, the most probable number is from 40 to 50,000 individuals. The Argentine National Institute of Statistics and Censuses (INDEC) gives a figure of 36,135 for Argentina only. 
In Rosario, the third biggest city of Argentina, there's a community of about 10,000 wichi people, all of them fluent in whichi, and some native speakers. There are even a couple of bilingual primary schools.