Most people are in Shenzhen are from other parts of China, you'll hear Mandarin (the default) Cantonese, Hakka, Hokkien etc - most people probably speak some di

Most people are in Shenzhen are from other parts of China, you'll hear Mandarin (the default) Cantonese, Hakka, Hokkien etc - most people probably speak some dialect of Mandarin as well as their birth language