Pinghua

Pinghua (; Yale: "Pìhng Wá"; sometimes disambiguated as /) is a pair of Sinitic languages spoken mainly in parts of the Guangxi Zhuang Autonomous Region, with some speakers in Hunan province. Pinghua is a trade language in some areas of Guangxi, where it is spoken as a second language by speakers of Zhuang languages. Some speakers of Pinghua are officially classified as Zhuang, and many are genetically distinct from most other Han Chinese. The northern subgroup of Pinghua is centered on Guilin and the southern subgroup around Nanning. Southern Pinghua has several notable features such as having four distinct checked tones, and using various loanwords from the Zhuang languages, such as the final particle "wei" for imperative sentences.
History and classification.
Language surveys in Guangxi during the 1950s recorded varieties of Chinese that had been included in the Yue dialect group but were different from those in Guangdong. Pinghua was designated as a separate dialect group from Yue by the Chinese Academy of Social Sciences in the 1980s and since then has been treated as a separate dialect in textbooks and surveys. 
Since designation as a separate dialect group, Pinghua has been the focus of increased research. In 2008 a report by the Chinese Academy of Social Sciences of research into Chinese varieties noted an increase in research papers and surveys of Pinghua, from 7 before the 1987 publication of the "Language Atlas of China" based on the revised classification, and about 156 between then and 2004.
In the 1980s the number of speakers was listed as over 2 million; and by 2016 as 7 million.
Pinghua is divided into two mutually unintelligible languages:
Phonology.
Nanning Pinghua has a voiceless lateral fricative for Middle Chinese /s/ or /z/, for example in the numbers "three" and "four". This is unlike Standard Cantonese but like some other Yue varieties such as Taishanese.
Tones.
Southern Pinghua has six contrasting tones in open syllables, and four in checked syllables, as found in neighbouring Yue varieties such as the Bobai dialect.
The split of the lower entering tone is determined by the initial consonant, with the low rising contour occurring after sonorant initials.
Anthropological.
Genetically, Pinghua speakers have more in common with non-Han ethnic minorities in southern China than with other Han groups.