as引导让步状语从句:表语/状语+as+从句,as意为:虽然…但是、尽管,通常从句要倒装,而用though引导让步状语从句时句子则不必倒装。

一、1、在引导让步状语从句的从属连词中,比较常见的有although, though, even though, even if, whether…or…等。
2、另外,以-ever结尾的连词如however, whatever, whoever, whenever, wherever等也可引导让步状语从句,其用法相当于no matter…。
3、注意,while和when除用于引导时间状语从句外,有时也可引导让步状语从句,其意为“尽管”“虽然”。

二、除了上诉常见的从属连词引导让步状语从句外,as 也可以引导让步状语从句,但是,as引导的让步状语从句必须以部分倒装的形式出现,被倒装的部分可以是表语、状语或动词原形,though也可用于这样的结构中,但although不可以这样用,例如:
引导让步状语从句时,as意为“虽然…但是”,“纵使…”之意”,“尽管”,通常从句要倒装,倒装的方法是将从句的表语或状语放在as之前,而用though引导让步状语从句时句字则不必倒装(口语中也可倒装).   

Heavily as it was raining outside, they started out very early.
 
尽管外面下雨非常厉害,但是他们早早就开始了。

Young as he is, he knows a lot=Though he is young 或Young though he is, he….

他虽然年轻,但懂得很多。
  
Object as/though you may, I’ll go.(=Though/Although you may object, I’ll go.)

纵使你反对,我也要去。

Hard as/ though he works, he makes little progress. (=Though he works hard,he makes little progress.)

尽管他学习很努力,但几乎没取得什么进步。

Child as/though he was, he knew what was the right thing to do.(=Though he was a child,he knew what was the right thing to do.)

虽然他是一个孩子,但他知道该做什么。

Fast as you read, you can’t finish the book so soon.

纵然你读得快,你也不能这么快读完这本书。

Lover of towns as I am, I realize that I owe a debt to my early country life.

尽管我爱城市,但我知道,以往的乡村生活使我受益匪浅。

Small as atome are, they are made up of still smaller units.
尽管原子很小,但它们由更小的单位构成。