Sundanese alphabet. Dinka is a member of the Western Nilotic branch of Nilo-Saharan languages. It is spoken mainly in southern Sudan by about 2-3 million people, who call them selves Dinka (Jiëŋ). There are five major dialect divisions: Ngok, Rek, Agaar, Twic/Twi East, and Bork, which are more or less mutually intelligible. The Rek dialect is considered the standard or prestige variety.