through Fur from the Blue Nile to reach the area of Sudan where they currently reside. Later, some Yulu were pushed farther west into the CAR. Many Yulu speakers prefer speaking Arabic, the official language of Sudan and one which was embraced by the academic community. In 1960, Arabic was required in education past grade 3 and through university. The Navaisha Peace agreement added more flexibility, though, by allowing small provinces to adopt local languages as official ones. Teachers and academics in the Bahr el-Ghazal region of Sudan have pushed for the more widespread use of local languages in schools, specifically pointing out that many, including Yulu, survived in books published by Catholic missionaries, which should be taken advantage of. Geographic distribution Yulu is not the dominant indigenous language in the region within which it is spoken, however, it is used over a wide geographic area, consequently making it difficult to know how many speakers there are. The estimated 7,000 speakers are divided between roughly 4,000 in the CAR and 3,000 in Sudan. Within the CAR, the language is spoken in the Ouadda-Djalél and Ouadda sub-prefectures, while in Sudan it is primarily spoken in the southwestern area of Darfur and Western Bahr el-Ghazal. A 2013 survey reported that ethnic Yulu reside in Dem Jalab Boma, Ringi Payam, Raja County, South Sudan. Phonology Consonants The following table provides an overview of the consonant phonemes. Vowels The following table provides an overview of the vowel phonemes. Vowel realizations Four of the vowel phonemes allophonically assume different vowel lengths depending on whether they have a high tone or a falling tone. Two of them also alternate vowel quality. /a/ does not face this alternation. Grammar One of Yulu's distinctive features is its system of four tones, classified as high, mid, low, and extra-low. It also boasts a relatively distinctive phenomenon of clustering verbs, anywhere between two and four at a time. These clusters work together to describe one process as if it were a single verb, and are not always distinguishable from one another within the cluster, in part because when one verb in a cluster ends in a vowel and the next verb begins with one, the two sounds overlap. These clusters are common in texts, and occur roughly 75% as often as single verbs. Verbs in Yulu always have a subject marker as well as a verb stem, and sometimes contain