Actually, Mandarin, at least according to this: https://www.quora.com/Do-people-in-Guangzhou-Shenzhen-and-Hong-Kong-speak-the-same-language https://www.quora.co

Actually, Mandarin, at least according to this: https://www.quora.com/Do-people-in-Guangzhou-Shenzhen-and-Hong-Kong-speak-the-same-language https://www.quora.com/Do-people-in-Guangzhou-Shenzhen-and-Ho...