if she comes,i will come.如果她来我就来
=i will come when she comes.当她来的时候我就来
i went back before it rains.我在下雨前回来了
=it doesn't rain until i went back.一直等到我回来才下雨.
两个例子你自己看看吧,其实转变主要看引导词的意思,还有就是位置
直接引语（过去时）变间接 when while before 等从句如何变
if she comes,i will come.如果她来我就来
=i will come when she comes.当她来的时候我就来
i went back before it rains.我在下雨前回来了
=it doesn't rain until i went back.一直等到我回来才下雨.
两个例子你自己看看吧,其实转变主要看引导词的意思,还有就是位置