If the young are the hope of the future, it is fitting that they should be at the forefront of a campaign to defend the Cantonese dialect. History, after all, shows that nations develop a stronger and more unified identity when regional cultures find free expression. Language lies at the root of a culture. If it dies out, the culture can follow over a few generations. Linguists say a language may be considered in danger when it is no longer passed by the older generation to the younger.

It is a worry, therefore, that on the mainland aspirational parents are abandoning native dialects at home in favour of Putonghua to give their children better access to education and jobs - even in Guangdong, the stronghold of Cantonese. And that in Hong Kong, more and more parents who want their children to attend prestigious international schools speak to them in less-than-perfect English, out of concern that if they speak Cantonese at home they will struggle to pass the entrance interview in English. Meanwhile, to meet parents' demands, the government has relaxed the mother-tongue policy to allow more teaching in English.

It would be premature on the strength of these trends to forecast the decline of Cantonese culture, but activists on both sides of the border have heeded warning signs. Those who attended a Guangzhou rally on Sunday plan to join another in defence of Cantonese in Wan Chai this Sunday. The catalyst for joining forces on a hotly debated issue was a controversial proposal to switch Guangdong TV programming from Cantonese to Putonghua to make it more visitor-friendly for the Asian Games in November.