Question

by which time during which time since when from where的详细用法、以

Answer 1

（1）by which time 引导定语从句,表示“到那个时候为止”.

（2）during which time引导定语从句,表示“在那期间“.

（3）since when引导时间状语从句.（when在这里作介词.注意了,when作介词时只有两种用法,就是since when和until when.）如：

Until when can you saty?你可以待到什么时候?

Since when have you got a new job?你从什么时候开始有了一份新工作?

（4）from where引导定语从句.可以换成from which.有人说from where似乎接的是大概的地点,from which接的是具体的地点.

不明白的再问哟,请及时采纳,多谢!