Across Taiwan, the standard language is 中文 (zhongwen), or Mandarin. Other prominent languages in Chiayi County, where I live, include Taiwanese and Tsou. On Lanyu, Mandarin is spoken, as well as some English, but the main language spoken is Tao, or Yami. Tao is the Indigenous language spoken by the Tao people who are native to Lanyu, and is closer to languages in the Phillipines than languages in Mainland China.
The money system used across all of Taiwan is the New Taiwan Dollar, or NTD. For reference $1 in U.S. dollars is equal to about $30 NTD. Goods in Taiwan are relatively cheap, and I can regularly purchase bubble tea (my favorite drink) for around NTD$45, or $1.50 in U.S. dollars.
A bottle of water at a 7-Eleven, the main convenience store in Taiwan, costs around $30 NTD or $1 U.S. dollar.
