Most people in Taiwan speak both Mandarin Chinese and Taiwanese (a variant Minnan dialect of southern Fujian province, China). Mandarin is taught in schools, however most spoken media is split between Mandarin and Taiwanese. Speaking Taiwanese under the localization movement has become a way for the pro-independence Taiwanese to distinguish themselves from the Mainlander. The Hakka, who make about 10 percent of the population, have a distinct Hakka dialect. The Aboriginal Taiwanese still speak their native languages, but most of them can also speak Mandarin, Taiwanese, and English. A large majority of people on Taiwan speak Standard Mandarin, which has been the only officially sanctioned medium of instruction in the schools for more than four decades.
Taiwanese Mandarin (as with Singlish and many other situations of a creole speech community) is spoken at different levels according to the social class and situation of the speakers. Formal occasions call for the acrotectal level of Guoyu, which in practice differs little from Putonghua. Less formal situations often result in the basilect form, which has more uniquely Taiwanese features. Bilingual Taiwanese speakers often code-switch between Mandarin and Taiwanese, sometimes in the same sentence.
Mandarin is spoken fluently by almost the entire Taiwanese population, except for some elderly people who were educated under Japanese rule. In the capital Taipei, where there is a high concentration of Mainlanders whose native language is not Taiwanese, Mandarin is used in greater frequency than in southern Taiwan and more rural areas where there are fewer Mainlanders.