What we really need are not English itself, but the rights "not to be obliged to use Mandarin." It's incredibly difficult for Taiwanese people nowadays to imagine a situation without Mandarin. Even though we all learned English in school, we don't use it in daily conversations. Simply imposing English-teaching lectures won't help.

Communication always takes the path of least resistance. In Taiwan, it is rare for two individuals capable of speaking both Mandarin and English to communicate in English.

However, if one person speaks Mandarin and English while the other speaks Taigi, English, and only has a basic grasp of Mandarin (for survival in Taiwan), they are more likely to have a conversation in English.

Speaking of the path of least resistance, it occurs to me that I once helped organize a symposium with around 80 participants, consisting of professors and post-docs who were all fluent in English. Except for one Indian and one American attendee, all participants were Taiwanese. As a result, all presentations were delivered in English.

However, during the poster session, when the two foreigners were not present, conversations predominantly took place in Mandarin (although English terminologies were still used).