by the time 的时态怎么用

题目

by the time 的时态怎么用
by the time 主句从句分别用什么时态 给几个例句

答案

1.表示将来的时间.
主句用将来完成时,而从句用一般现在时来表示将来的动作.
如:I will have finishied the work by the time my father comes back.
2.表示过去的时间.
主句用过去完成时,而从句用一般过去时.
如：He had built a lab for himself by the time he was 12 years old.