题目内容：

主句过去时,if引导的从句什么时?

优质解答

这个要看情况的.1.if作如果的时候,用过去式.例：He decided to leave if she didn't come in ten minutes.2.if作是否的时候,用过去将来式.例:he wasn't sure if she would come in ten minutes.3.当然还有其他情况要...