Zambia tributaries rise in Angola's central highlands. The edge of the Cuando River floodplain (not its main channel) forms Zambia's southwestern border, and via the Chobe River that river contributes very little water to the Zambezi because most is lost by evaporation. Two of the Zambezi's longest and largest tributaries, the Kafue and the Luangwa, flow mainly in Zambia. Their confluences with the Zambezi are on the border with Zimbabwe at Chirundu and Luangwa town respectively. Before its confluence, the Luangwa River forms part of Zambia's border with Mozambique. From Luangwa town, the Zambezi leaves Zambia and flows into Mozambique, and
Tonga people (Zambia and Zimbabwe) and 137,000 in Zimbabwe; it is an important lingua franca in parts of those countries and is spoken by members of other ethnic groups as well as the Tonga. Tonga also speak Shona and Ndebele in Zimbabwe, English in Zambia and Zimbabwe, and Portuguese in Mozambique as second languages. Tonga people (Zambia and Zimbabwe) The Tonga people of Zambia and Zimbabwe (also called 'Batonga') are a Bantu ethnic group of southern Zambia and neighbouring northern Zimbabwe, and to a lesser extent, in Mozambique. They are related to the Batoka who are part of the Tokaleya people in the same area,