There are official spies and then others who may be tasked with more general “find out what you can” kind stuff? The linked article seemed to say sort of that; how many Chinese students here are from “connected” families? CCP, military, government families? Probably a huge percentage. Maybe you can find out from some familiar with Chinese language whether he has a Taiwan or mainland accent? I would assume there are accents.
Good idea. I do know two other Chinese bridge players (married) who would know but I’m 95% sure they really are spies. They’re very secretive about everything, especially the husband’s work, and both take frequent trips to China throughout the year. Asking either of them anything would be like talking to a painting, especially if they’re all spies.
It's beyond accent. There are at least 7 variants of Chinese that are as different as French and Spanish. Chinese variants share a common written language, but the spoken languages are unintelligible to people who speak another variant. Most on the mainland speak Mandarin. Most in Taiwan speak Cantonese.