334　hardly/scarcely…when/before和no sooner…than

◎ 这几种结构均表示“刚一……就”，只是hardly/scarcely…when/before 比no sooner…than 更为正式。表示过去的行为动作时，hardly，scarcely和no sooner 引导的从句通常用过去完成时，when，before和than 引导的从句用一般过去时。hardly，scarcely和no sooner 位于句首时，要用部分倒装。

Hardly had I got into the office when the telephone rang. 我刚进办公室电话铃就响了。

Hardly had we reached the mountain top when it began to rain. 我们刚到山顶就下起雨来。

No sooner had he returned home than he was arrested. 他刚一踏进家门就被逮捕了。

No sooner had the moon appeared then it was clouded over. 月亮刚刚露出脸儿，就被乌云遮住了。

Scarcely had I opened the door when the dog came running in. 我一开门狗就跑了进来。

比较

（不可用than）

no sooner…than（不可用when或before）