The Hong Kong Special Administrative Region of the People’s Republic of China has long been a bilingual place. However, for the majority of the population, their first language is not Mandarin (普通話) but Cantonese (粤語 or 廣東話). Cantonese is recognizably a member of the great Sino-Tibetan family of languages. With about 70 million native speakers, it is one of the largest languages in the world. It is spoken in both the Hong Kong SAR and the Macau SAR, not to mention in China’s Guangdong Province and overseas.
The Chinese people have historically coped with the wide differences between dialects and local accents through writing. In formal writing, Hong Kong Chinese would essentially use Mandarin grammar while using Cantonese pronunciations. However, there are publications in Cantonese itself, using specially devised characters to cope with some of the differences between Mandarin and Cantonese. Cantonese is the only Chinese language to have done so and it is only in Hong Kong where one might see these special characters. The late Chairman Mao did not speak Mandarin as a native. As I understand it, his native language was Xiang ( 湘語), a language spoken among the natives of Hunan Province. He did not speak Mandarin fluently. Both the Republic of China, now in exile on Taiwan and the People’s Republic of China have sought to impose Mandarin as the official standard. Mandarin is the language of education in Taiwan and Mainland China both, though now both places have television and radio broadcasts in the local languages along with Mandarin. Mandarin has long had great prestige, mostly because of its use in the imperial court in Beijing. It was the language of government officials. In Taiwan, it is known as guoyu (國語), meaning “national language”. In Beijing and Singapore, it is putonghua (普通話)
In Singapore, the government has long encouraged all those of Chinese descent to learn Mandarin. To that end, radio and television broadcasts in the locally spoken Hokkien and Cantonese dialects were ended. I have heard that popular Taiwanese broadcasts, which happen to be in the Taiwanese form of the Hokkien languages (福佬話) have to be translated into Mandarin before being shown in Singapore, as Singaporean law does not permit the broadcasting of Chinese language broadcasts in any other language than Mandarin.
In 1997, British rule came to an end and the Chinese resumed control of Hong Kong island, Kowloon, and the New Territories. While Cantonese remains widely spoken and understood, Mandarin is heard more and more. The MTR subway now provides announcements in Cantonese, Mandarin, and English. Radio Television Hong Kong broadcasts in Cantonese, though they are now broadcasting in Mandarin, too. Shanghaiese is another of China’s regional languages, though I’ve heard that only about half of Shanghai’s residents can speak it. More and more Hong Kong residents are learning Mandarin.
Some Hong Kong parents, in a bid to enroll their young in international schools where they can gain competence in both English and Mandarin aren’t speaking Cantonese at home, but instead speaking only Mandarin and/or English. This does not bode well for the future of Cantonese. While Cantonese hasn’t reached the level of an endangered language yet, as this piece in the China Post points out, some Chinese linguists are clearly worried. You can read more here.