Tongyong Pinyin
In Mandarin Chinese, the surname is transliterated as Cài in pinyin and Tongyong Pinyin, Ts'ai in Wade-Giles, and Tsay in Gwoyeu Romatzyh. In Southern Min or Taiwanese, it is Chhoà in Pe̍h-oē-jī. In Cantonese (Hong Kong and Macau), it is Coi3 in Jyutping and Choi in Yale. (This should not be confused with the predominantly Korean family name Choi which has a different character [崔]). In Hakka it is Tshai in Pha̍k-fa-sṳ. (In Tongyong pinyin, it is Cai in Siyen Hakka and Ca̱i in Hoiliuk Hakka.) In Fuzhou dialect, it is Chái (in Bàng-uâ-cê).