Do they speak Mandarin or Cantonese in Shenzhen/ Guangdong?
They know both languages but cantonese is a dialect which is another form of chinese. The writings are nearly the same. Hong Kong and macau use traditional chinese characters while the rest of China use simplified chinese. And cantonese is the mother or local language of guangdong people. I born in hong kong and I can speak and write both cantonese and mandarin but I prefer to use cantonese as my first language at home because I like the majority of guangdong people more fluent in the cantonese language. The other yahoo users who posted above me are right, as there are more people coming from other china’s provinces, mandarin is the common language. Hope this helps.