Taiwanese Mandarin, Guoyu () and colloquially as Huayu () refers to Mandarin Chinese 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, commonly called Minnanyu (), Southern Min, Taigi or Hokkien. This language has had significant influence on Mandarin as spoken on the island. Guoyu is not the indigenous language of Taiwan. Chinese settlers came to Taiwan in the 16th century, but spoke other Chinese languages, primarily Southern Min, and Taiwanese indigenous peoples speak unrelated Austronesian languages. Japan annexed Taiwan in 1895 and governed the island as a colony for the next 50 years, during which time Japanese was introduced and taught in schools. With the defeat of Imperial Japan in World War II, Taiwan was handed to the Republic of China under the Kuomintang (KMT), which by 1950 had been pushed by the Chinese Communist Party (CCP) out of the mainland. The KMT promulgated Standard Mandarin as the national language while suppressing non-Mandarin languages in the public sphere in Taiwan. At the same time, in the People's Republic of China on the mainland, Putonghua () was likewise promoted as the national language. Putonghua in mainland China and Guoyu in Taiwan are highly similar and derive from the same standard based on the phonology of the Beijing dialect of Mandarin Chinese and the grammar of written vernacular Chinese in the early 20th century. Standard Guoyu pronunciations tend to be based on prescribed dictionaries of the period, whereas Standard Putonghua integrated colloquial Northern Mandarin pronunciations for some words. Notable characteristics of Guoyu as is commonly spoken in Taiwan include its somewhat different tonal qualities compared to Putonghua, the lack of the erhua phenomenon, and the lack of retroflex consonants (with zh-, ch-, sh- being pronounced like z-, c-, and s-). Guoyu also incorporates vocabulary from Minnanyu and Japanese. Written Chinese (both Guoyu and Chinese languages like Hakka and Minnanyu) in Taiwan generally uses traditional characters, in contrast to mainland China, excluding Hong Kong and Macau, where simplified Chinese characters were adopted beginning in the 1950s. Some grammatical differences also exist, often due to the influence of Minnanyu. The two forms of Mandarin evolved additional differences over the decades of political separation between the Republic of China in Taiwan and the People's Republic of China in the mainland, though both remain mutually intelligible. Guoyu