since引导的从句是什么时态

问题描述:

since引导的从句是什么时态
1个回答 分类:英语 2014-12-11

问题解答:

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可以是过去时也可以是过去完成时.如果是过去时它的从句用现在完成时,如果是过去完成时它的主句用过去时.如 It is /has been five years since he came here.(只有这种句型主句可用一般现在时代替现在完成时.)
It was five years since he had come here.
 
 
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