Taiwanese Mandarin, referred to as Guoyu (Chinese: 國語; pinyin: Guóyǔ; lit. 'national language') or Huayu (華語; Huáyǔ; 'Chinese language') in Taiwanese Mandarin, is the variety of Mandarin spoken in Taiwan. A large majority of the Taiwanese population is fluent in Mandarin, though many also speak a variety of Min Chinese known as Taiwanese Hokkien, which has had a significant influence on the Mandarin spoken in the Republic of China (Taiwan), including Taiwan proper and its surrounding islands.
Mandarin was not a prevalent spoken language in Taiwan before the mid-20th century. Early Chinese immigrants who settled in Taiwan before Japanese rule mainly spoke other varieties of Chinese languages, primarily Hakka and Hokkien. By contrast, Taiwanese indigenous peoples speak unrelated Austronesian languages. Japan annexed Taiwan in 1895 and governed the island as a colony for the next 50 years, introducing Japanese in education, government, and public life. With the defeat of Imperial Japan in World War II, Taiwan was transferred to the Republic of China, ruled by the Kuomintang (KMT), which by 1950 had been expelled from the mainland by the Chinese Communist Party (CCP). The KMT promulgated Standard Mandarin known as Guoyu in Taiwan while suppressing non-Mandarin languages in the public sphere. At the same time, the People's Republic of China promoted the same national language as Putonghua (普通话; 普通話; Pǔtōnghuà; 'common speech') on the mainland.