1. 作"当……的时候",引导时间状语从句。注意与when、 while的用法区别。
When he was at college, he could speak several foreign languages.
When the clock struck twelve, all the lights in the street went out.
Work while you work. Play while you play.
③ 但属下列情形时,只用as, 而不用when或while。
The girl dances as she sings on the stage.
He looked behind from time to time as he went forward.
As time went on / by, she became more and more worried.
As children get older, they become more and more interested in the things around them.
I thought of it just as you opened your mouth.
Just as the flying worm hit her face, she gave a loud cry.
As a young man, he was active in sports.
2. as=since, 作"既然"、"由于"解,引导原因状语从句,常用来表示已为人们所知或显而易见的原因或理由。如:
As / Since you''''re not feeling well, you may stay at home.
As he wasn''''t ready in time, we went without him.
3. as=in the way that, 作"像"、"按照……的方式"解,引导方式状语从句。如:
He speaks English as Americans do.
Remember, you must do everything as I do.
4. 用于as...as...或not so/ as...as...中,前一个as是副词,后一个as是连词,引导比较状语从句。如:
They helped the old man as often as possible.
I don''''t speak English so/ as well as he does.
5. 作"虽然"、"尽管"解,引导让步状语从句。常用倒装语序,即adj. /adv. / n.+as +主语+谓语+主句。如:
Tired as they were, they walked on.
Child as he is, he knows a lot. (child前不用冠词)
He is very careful, as his work shows.
As is well-known, Taiwan belongs to China.
is known to everybody, the moon travels round the earth once every month.
A. It B. As C. That D. What
另外,当先行词被the same, such等词修饰时,常用as来引导定语从句。如:
Such a clever boy as he can learn anything quickly.
I was reading the same book as he bought yesterday.
As a League member, I''''ll take the lead in everything. (状语)
She works as a doctor. (状语)
They have me as one of their own children.(引起宾语补足语)