“主将从现”,只适合【状语从句】,包括由if,unless 等引导的【
条件状语从句】和由when,
as soon as等引导的【
时间状语从句】.如：I will call you as soon as I get there./ If it doesn't rain tomorrow,we'll go on a picnic.,这两个句子都是典型的“主将从现”的句子.
As long as 能引导条件状语从句吗,是不是主将从现
可以引导条件状语从句,如果是指将来的动作,要主将从现
如：
As long as you help us,we shall finish the task
in time.
只要你帮助我们,我们就会按时完成任务
as引导时间状语从句，主句和从句应用什么时态？
As作连词引导时间状语从句时,着重强调主句和从句中的动作同时发生,并且从句通常放在主句之前。归纳起来有下列两种情况:
1)状语从句的
谓语动词是持续性动词,从句时态常用进行时态。
如: ①As he Was waiting,he suddenly heard a voice from above……
②As Bethune and the other doctors were climbing the hills,they could see the enemy entering the village in the valley below.
2)状语从句的谓语动词是终止性动词,从句时态常用一般时态。
如: ①As she stood there,she heard the first bell.
②As they looked up,they saw another cloud coming towards them.
③As they watched.it came nearer and nearer.