As 的用法小结 as 可以作连词、介词及关系代词和副词。现将其用法小结如下: （一）、 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. 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 he’s been ill for ages, I will help him. As / Since you're not feeling well, you may stay at home. As he wasn't ready , 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: Do as I told you. 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 as much as possible. I don't speak English so/ as well as she does. 5. 表示虽然,尽管 等,引导让步状语从句,常用倒装语序,模式为: adj. ...
