Which dialect(s) to study before visiting Shenzhen? I'm looking at travelling to Shenzhen for a month. Which dialect(s) should I study? For speaking with factory managers, workers, and for day to day life?
Shenzhen is in mainland China, so you should study Mandarin. However, it is so close to Hong Kong, and there is a lot of business between Hong Kong and Shenzhen if you know a bit of Cantonese, it will suffice also.