三、从属连词

　　1. 引导时间状语从句的连词

　　这类连词主要有：

　　when:

　　Don’t get excited when you talk. 讲话时别激动。

　　When he got up he felt dizzy. 他站起身时感到头晕。

　　while:

　　We must strike while the iron is hot. 我们要趁热打铁。

　　While she ate she grew more restless. 她一边吃一边变得更加忐忑不安。

　　as:

　　As he spoke two men came up. 在他讲话时两个人走了进来。

　　He smiled as he passed. 他经过时笑了笑。

　　before:

　　Look before you leap. 三思而后行。

　　It will be five years before we meet again. 要五年后咱们才能再相见。

　　after:

　　I arrived after he had left. 在他走后我到了。

　　I’ll tell them after you have left. 你走后我在告诉他们。

　　until, till :

　　I’ll take no steps until you arrive. 你来之前我不会采取什么行动。

　　I propose waiting till the police get here. 我建议等警察来了再说。

　　since:

　　How long is it since you came to London? 你到伦敦有多久了?

　　It was years since I had seen her. 我有好多年没见到她了。

　　whenever:

　　I go and visit him whenever I’m in town. 我每次进城都去看他。

　　Whenever possible, they play outside. 一有机会他们就到外面玩耍。