not until在句首可以用过去完成时吗?

可以。 当Not until位于句首时,句子要倒装。其结构为:Not until+从句/表时间的词+助动词+(主句)主语+谓语+。如:1。 Not until he had accomplished his mission did he realize that he was seriously ill。直到他完成了使命他才意识到自己病得多重。 2。 Not until the teacher came in did the students stop talking。直到老师进来学生们才停止讲话。 3。 Not until next week will the sports meet be held。直到下周才开运动会。 再问： 那如何区分用过去完成时和过去时呢 再答： 应该是根据句意吧。