y the time是从前面的时间开始一直到那个时间点的状态
when则只是表述那个时间点的动作或状态.
by + 过去的时间点.如：I had finished reading the novel by nine o'clock last night.
When I woke up,it had already stopped raining.
when和by the time用在过去完成时有什么区别?
y the time是从前面的时间开始一直到那个时间点的状态
when则只是表述那个时间点的动作或状态.
by + 过去的时间点.如：I had finished reading the novel by nine o'clock last night.
When I woke up,it had already stopped raining.