It is widely taken for granted that people in Taiwan speak Mandarin. Suppose a foreigner and a Taiwanese both speak English and Mandarin. I have heard foreigners asking: “Why do Taiwanese speak English to me while I speak Mandarin?”They have a point, certainly. According to that view, Taiwanese who prefer to speak English with Westerners who can speak Mandarin on Taiwan’s soil seem to lack cultural self-esteem. So speaking English is totally fine.

Source: Taipei Times March 02, 2020 16:07 UTC