You're right about Bopomofo - both it and pinyin are based on the same pronunciations so there's actually a one-to-one correspondence between the two systems:

You're right about Bopomofo - both it and pinyin are based on the same pronunciations so there's actually a one-to-one correspondence between the two systems: https://en.wikipedia.org/wiki/Bopomofo#Pinyin https://en.wikipedia.org/wiki/Bopomofo#Pinyin