同学你好，该知识点来自沪江网校《新概念英语第四册【随到随学班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好~
在含有否定副词的句子当中，如never, seldom, rarely, little, hardly, scarcely, no sooner, no longer, nowhere 等这些含有否定意义的副词位于句首时，则其后要用部分倒装，例如：

I shall never tell him. / Never shall I tell him. 我永远不会告诉他。

He seldom does work at home. / Seldom does he do work at home. 他很少在家工作。

She hardly has time to have a cup of tea with her friends. / Hardly does she have time to have a cup of tea with her friends. 她几乎没时间和她朋友一起喝茶。

He little realizes how important this meeting is. / Little does he realize how important this meeting is. 他不明白这个会议的重要性。

We had no sooner reached the airport than the plane took off. / No sooner had we reached the airport than the plane took off. 我们刚到机场,飞机就起飞了。

对于not…until句型，当not until…位于句首时，其后的主句要用倒装语序：
He didn’t leave the room until the rain stopped. / Not until the rain stopped did he leave the room. 雨停了之后他才离开这房间。

祝同学学习进步~