考研英语常用词汇：as的用法总结

When I was at college, I could speak several foreign languages.

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：He was watching TV while his mother was cooking.

2．as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。与because，since相比，as一般放在句首，语气较弱，较口语化。如：

As you’re not feeling well, you may stay at home.

As he wasn’t ready, we went without him.

3．as作“像”、“按照……的方式”解，引导方式状语从句。如：

Leave things as they are.

Remember, you must do everything as I do.

4．表示“虽然，尽管”，引导让步状语从句，多在主句之前，且常用倒装语序，模式为：adj. /adv. /n. /v. as 主语 谓语 主句。如：

Young as he is, he knows much about electricity.

Try as he did, he failed again.

知识拓展：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 help the old as much as they can.

I don’t speak English as well as she does.

（二）as作从属连词引导定语从句时，表示“正如”：

1．引导限制性定语从句。如：

He isn’t the same person as he used to be．