The younger Taiwanese generation often speaks English as a second language, but it isn't spoken as a first language. Taiwan also exports a lot - examples Latex Gloves. English is also spoken almost...
Most speak Mandarin, but 70% also speak Hokkien-Taiwanese. If you go more into the mountains/country, you will notice that they speak more Hokkien and that their Mandarin has a heavier Hokkien accent.