【as作连词的用法】as当...时候是连词

　　下面是小编为同学们整理了as作连词的用法 ，希望大家学以致用!

　　as作连词的用法:

　　1.作“在-------期间，当----的时候”引导时间状语从句.注意与when、 while的用法区别。

　　①下列情形时,只用as, 而不用when或while。

　　1)用于表示同一个人的两种动作交替进行,指一边----一边. 如:

　　The girl sings as she goes to school.

　　He looked behind occasionally as he went forward in the forest.

　　2)表示两个同步发生的动作或行为,意思是随着-----的发展.如:

　　As time went on / by, she became more and more beautiful .

　　As children get older, they become more and more interested in everything.

　　3)表示两个短暂行为或事情几乎同时发生.如:I watched her as she read the book.

　　I thought of it just as you opened your mouth.

　　Just as the flying worm hit her face, she gave a loud cry.

　　4)接在名词后面表示某一个年龄段时.如:

　　As a young man, he was active in sports.

　　②when作"当……的时候"解,可以指较短的(一点)时间,也可指一段时间。如:When I was at college, I could speak several foreign languages. When the clock struck twelve, I had slept for 2hours.

　　③ while常表示一段较长的时间或一个过程,强调主句谓语动词与从句谓语动词同时发生。如:Work while you work. Play while you play.