Longdu dialect
The Longdu dialect is a variety of Southern Min Chinese language originating from the towns of Dachong and Shaxi in Zhongshan in the Pearl River Delta of Guangdong. The two regions Shaxi and Dachong are together informally known as Longdu region to the local people and overseas. There are more than 40 villages in the region and is held together by their shared dialect, which may be classified as endangered due to its deterioration in status and rapidly decreasing popularity even within its own Longdu region. Despite its close proximity, Longdu dialect is not very closely related to  the surrounding dialects in the region, which belong to the Yue group. As such, Longdu forms a "dialect island" of Min speakers. It is one of three enclaves of Min in Zhongshan, the others being Sanxiang and Nanlang. Its native speakers generally understand Cantonese, but not vice versa. "A lot of children do not speak the language in their daily lives. The population of speakers is diminishing." According to Søren Egerod, who published an extensive study of the dialect based on fieldwork conducted in 1949, the vocabulary consists of three layers: The Longdu dialect is a mother tongue of many  oversea Chinese and is slowly disappearing due to the emigration of people from the Longdu region to other countries, and due to the lack of inter-generational knowledge sharing. Parents and grandparents teach the children only Cantonese given that the Longdu region is within Zhongshan, Guangdong. At school, only Mandarin is taught to children because Mandarin is the official national language, and Cantonese is generally viewed as the official language of the Guangdong province.