Uduk, also known as Tw'ampa, is a Koman language spoken in the Gambela region

Gambela Region

Gambela is one of the nine ethnic divisions of Ethiopia. Previously known as "Region 12", its capital is Gambela. Lying between the Baro and Akobo Rivers, the western part of Gambela includes the Baro salient....

 in western Ethiopia

Ethiopia

Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

, and across the border in the Upper Nile state of South Sudan

South Sudan

South Sudan , officially the Republic of South Sudan, is a landlocked country located in the Sahel region of northeastern Africa. It is also part of the North Africa UN sub-region. Its current capital is Juba, which is also its largest city; the capital city is planned to be moved to the more...

. It is spoken by approximately 20,000 people in Ethiopia; the number of speakers in South Sudan is unknown (Ethnologue 2009). The Koman languages are a
close-knit group which are often held to include the now extinct language of Jebel Gule and, on a
deeper level, to be related to Gumuz

Gumuz language

Gumuz is a dialect cluster spoken along the border of Ethiopia and Sudan. Most Ethiopian speakers live in the Metekel Zone of the Benishangul-Gumuz Region, although a group of 1,000 live outside the town of Welkite...

 and many other languages under the Nilo-Saharan umbrella
(Bender 1983).