Chengdu-Chongqing dialect or Cheng–Yu (; Sichuanese Pinyin: Cen2yu2, ) is the most widely used branch of Southwestern Mandarin, with about 90 million speakers. It is named after Chengdu, the capital city of Sichuan, and Chongqing, which was split from Sichuan in 1997. It is spoken mainly in northern and eastern Sichuan, the northeastern part of the Chengdu Plain, several cities or counties in southwestern Sichuan (Panzhihua, Dechang, Yanyuan, Huili and Ningnan), southern Shaanxi and western Hubei. This uniform dialect is formed after the great migration movement in Ming and Qing dynasty, and is greatly influenced by the Chinese varieties of Mandarin the immigrants spoke from Hubei, Xiang and Gan. So it keeps fewer characteristics of Sichuan's original Ba-Shu Chinese than other Sichuanese dialects, such as Minjiang dialect. Distributions Chengdu-Chongqing Dialect is spoken within central Chongqing, Chengdu and surrounding provinces. Chengdu-Chongqing dialect is a branch of Sichuan dialect. Academically, Chongqing dialects are spoken in main urban area of Chongqing, with one-fifth population of the Chongqing city. In a broad sense, Chongqing dialect is spoken with all districts of Chongqing City. Eg: Tongliang District, Hechuan District, Fuling District, Zhanjiang District, etc. Chongqing dialect its considered as a branch of Southwestern Mandarin. The Chengdu-Chongqing dialect is mutually intelligible with dialects spoken in its satellite districts such Sichuan. But, as all public schools and most broadcast communication in urban Chongqing use Mandarin exclusively, nearly all speakers of the dialect are good at Chongqing dialect and Mandarin. Owing to migration within China, traditional Chongqing dialect is getting similar to Mandarin, many residents of the city cannot speak the local dialect but can usually understand it, and get fluent to it after a few months or years in the area. History With Chinese government declared movement to Chongqing during the World War II, Chongqing became the Provisional capital of the republic of China, when migration boost the population of the city. Chongqing dialect mixes the merits of various local dialects, with wits and humor, gains popularity with its users. Phonology Tone Chengdu-Chongqing dialect has four phonemic tones: dark level tone, light level tone, rising tone and departing tone. These tones are of same pitch as Sichuan dialects (Minjiang, Renfu, Yajin). Initial The Chengdu-Chongqing dialect in most regions doesn't have tongue retroflex (tʂ group initials), except for Bazhong district and Panxi area (except for Panzhihua), where the consonants of the tongue curling are similar but not the