What must one do if he wants to learn another language well?

问题描述:

What must one do if he wants to learn another language well?
What must one do if he wants to learn another language well?

如果一个人想要学好另外一种语言,那他必须干些什么?
这是一个典型的由if引导的条件状语从句.
主情从现.