①此类连词主要有：when, while, after, before, as, as soon as , until, till, once, since, whenever, no sooner…than, hardly/barely/scarcely…when等。
When I got to the theatre, I found that they had sold all the tickets.当到达剧院时，我发现票已售完。
We should strike while the iron is hot.我们要趁热打铁。
Since he entered the university, he has made great progress in his studies.
They kept on working until it became dark.他们一直工作到天黑。
Once you begin , you must go on. 你一旦开始，就必须继续下去。
You seem to have a ready-made answer, whenever I ask you a question.
Now (that) you are here, you’d better stay.你既然来了，那就不要走了。
No sooner had they got to the field than it began to rain.他们刚到田里就开始下雨了。
Hardly had he set foot on his native land when he felt comfortable.
注意：no sooner, hardly等位于句首时需用倒装语序。
②every time, each time, next time, the last time, the moment, immediately等，引导句子其作用相当于一个时间状语从句。
She felt a thrill the moment she got into the theatre.她一进剧场就感到一种激动。
Every time he got to Beijing, he came to see me.每次他来北京，他都来看我。