With the defeat of Imperial Japan in World War II, Taiwan was handed 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).

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.

[10] Some scholars have argued that Putonghua and Guoyu are artificial standards that, strictly speaking, do not represent the natively spoken language of a significant number of, or even any, people.

[note 3] More formal settings—such as television news broadcasts—tend to feature speakers using Standard Guoyu, which closely resembles mainland Putonghua, but is not generally used as a day-to-day language.

In the centuries following Chinese settlement, the number of indigenous languages dropped significantly, with several going extinct, in part due to the process of sinicization.

[24] After its defeat in the First Sino-Japanese War, the Qing dynasty ceded Taiwan to the Empire of Japan, which governed the island as an Imperial colony from 1895 to 1945.

[24] After the Republic of China under the Kuomintang (KMT) gained control of Taiwan in 1945, Mandarin was introduced as the official language and made compulsory in schools, although the local population rarely spoke it at the time.

[25] Many who had fled the mainland after the defeat of the KMT by the Communists also spoke non-standard varieties of Mandarin, which may have influenced later colloquial pronunciations.

[26] Wu Chinese dialects were also influential due to the relative power of KMT refugees from Wu-speaking Zhejiang, Chiang Kai-shek's home province.

[31] English and "mother tongue education" (母語教育; mǔyǔ jiàoyù) — Hokkien and Hakka — were introduced as elective subjects in primary school in 2001.

[32] Greater time and resources are devoted to both Mandarin and English, which are compulsory subjects, compared to mother tongue instruction.

In the capital of Taipei, where there is a high concentration of Mainlander descendants who do not natively speak Hokkien, Mandarin is used in greater frequency and fluency than in other parts of Taiwan.

[35][note 5] Overall, while both national and local levels of government have taken some measures to promote the use of non-Mandarin Chinese languages, younger generations generally prefer using Mandarin.

Taiwan is the only Chinese-speaking polity to use the system, which is taught in schools (often used as ruby characters to aid young learners) and represents the dominant digital input method on electronic devices.

[55] In 1984, Taiwan's Ministry of Education began revising the Gwoyeu Romatzyh method out of concern that Hanyu Pinyin was gaining prominence internationally.

[71] Often the reduction involves the removal of initials in compound words, such as dropping the t in 今天 jīntiān 'today' or the ch in 非常 fēicháng 'extremely, very'.

This is especially prominent in words and phrases which refer to things or concepts invented after the split; thus, modern scientific and technological terminology often differs greatly between Putonghua and Guoyu.

[93][96] For instance, Zhang (2000) selected four hundred core nouns from computer science and found that while 58% are identical in Standard and Taiwanese Mandarin, 22% were "basically" or "entirely" different.

[98] For example, the words 瓶頸 (瓶颈) píngjǐng 'bottleneck' and 作秀 zuòxiù 'to grandstand, show off' were originally unique to Guoyu in Taiwan but have since become widely used in mainland China as well.

For example, in Taiwan, bubble tea, 珍珠奶茶 zhēnzhū nǎichá, is often abbreviated 珍奶 zhēnnǎi, but this is not common on the mainland.

For example, Taiwanese Mandarin users strongly prefer 要 yào and 不要 búyào over 得 děi and 別 bié, respectively, to express 'must' and 'must not', compared to native speakers from Beijing.

[91] Some of the vocabulary differences stem from different social and political conditions, which gave rise to concepts that were not shared between the mainland and Taiwan, e.g. 福彩 fúcǎi, a common abbreviation for the China Welfare Lottery of the People's Republic of China, or 十八趴 shíbāpā, which refers to the 18% preferential interest rate on civil servants' pension funds in Taiwan.

[118] 啦 lā is a very common modal particle in Guoyu, which also appears in Putonghua with less frequency and always as a contraction of 了 le and 啊 a.

In Guoyu, it has additional functions, which Lin (2014) broadly defines as "to mark an explicit or implicit adjustment" by the speaker to a given claim or assessment.

[119] In more specific terms, this use includes expression of impatience or displeasure (a, below); an imperative, such as a suggestion or order, especially a persistent one (b), and rejection or refutation (c).

Thus, words like 阿妹 āmèi 'younger sister' may be used instead of the standard 妹妹 mèimèi, and public figures like Tsai Ing-wen may be referred to as 阿英 Āyīng.

The Japanese language saw the proliferation of neologisms to describe concepts, and terms learned through contact with the West in the Meiji and Taishō eras.

[9][141] For example, the Hokkien word 摃龜 (Peh-oe-ji: kòngku; [kɔŋ˥˩ku˥˥]) 'to lose completely', which has been borrowed into Guoyu, originates from Japanese sukonku (スコンク, 'skunk'), with the same meaning.

[142] Other examples of Guoyu loans from Japanese via Hokkien include 運將 yùnjiàng, 'driver, chauffeur', from 運ちゃん unchan and 歐巴桑 ōubāsāng, 'elderly woman', from おばあさん obāsan.

To mark the perfect verbal aspect, Guoyu employs 有 (yǒu) where 了 (le) would be used in the strictly standard form of the language.