状语从句We were about to set off when it suddenly began to rain.我们刚要出发，突然下起雨来。We were having a meeting when someone broke in.我们正开着会突然有人闯入。He had just fallen asleep when the phone rang.他刚刚睡着电话就响了。1．When 引导时间状语从句，意为“正在这时”，常用于以下句式： be about to do ...when...be doing ...when...be on the point of doing...when...had just done...when... 注意： when 可表原因，意为“既然”。(2007· 山东卷 )How can you expect to learn anything when you never listen. 既然你什么也听不下去你怎么期望学东西呢？2 ． as soon as ， immediately ， directly ， instantly ， the moment ， the minute ， the instant ， no sooner...than... ， hardly/scarcely...when... 和 once(…………一就)这些从属连词引导的从句都表示从句的动作一发生，主句的动作随“…………”即就发生，常译为 一就。从句中用一般时态代替将来时态。The moment I heard the voice ， I knew father was coming.我一听到那个声音，我就知道父亲来了。No sooner had we arrived at the station than the train left.我们刚到车站，火车就离站了。The boy burst into tears immediately he saw his mother.那男孩一见到他妈妈便放声大哭。My sister came directly she got my short message.我姐姐一收到我的短信就来了。3 ． on doing sth./on one’s ＋ n.“…………”也可表示 一就，引导时间状语。On arriving at the station ， the thief was caught.贼一到车站就被抓了。On his arrival in London ， he called his father up.他一到伦敦就给他父亲打了个电话。4 ． before(1)“…………………………………若表示 还未就；不到就；才；趁……………”；还没来得及就时，需用连词 before 。He rushed out of the room before I told him the news.我还没来得及告诉他消息，他就冲出了房间。Please write it down before you forget it.趁你现在没忘把它记下来。(2)It will be ＋一段时间＋ before...……多久之后才It will be half a year before I come back.还得呆半年我...
