Swahili is the lingua franca of east and south west Africa. It is spoken and understood at least in Tanzania, Kenya, Uganda, Rwanda, Burundi, Mozambique and in the Democratic Republic of Congo. It is the official mother tongue of only 5–15 million people, but the estimations of how many people actually speak Swahili vary between 60 and 150 million.
Because of the influence of the Arabic Muslims on the Swahili coast there are a lot of Arabic words in the language, but it also has influences from the colonial time period and you can hear this in the loan words from German, Portuguese, English, Hindi and French.
Jan Knappert (1927–2005), who was a Dutch linguist and researcher on literature, translated the Kalevala into Swahili in 1992.