Do Hong Kong people born in Hong Kong before the return to China have British nationality? Will their nationality become Chinese after the return to China?

No! Of course not! Previously, it was only counted as a Commonwealth area, and the nationality of Hong Kong people was not accurately classified. It only referred to Hong Kong people. Because before the handover, Hong Kong was considered a highly autonomous region. Big things have to be approved by the UK. Of course, it was much easier for them to go to the UK and other Commonwealth areas than it was for us, but they did not have British citizenship. They were second-class citizens at the time. Now they are authentic Chinese and have Chinese nationality.