I guess it depends on the language they are using at the specific moment. People in Hong Kong are probably going to pronounce it in Cantonese. Border guards in

I guess it depends on the language they are using at the specific moment. People in Hong Kong are probably going to pronounce it in Cantonese. Border guards in Beijing will probably pronounce it in Mandarin. There is actually no good way to tell whether a name is Mandarin or Cantonese, except maybe by looking at the place of birth or residence. Ironically, the romanized form might give clues as there are many different romanization systems in use.