As
conj 连词
1. 在......期间 当......时候
2由于,应为
3尽管，即使，虽然
4如.......一样, 像......一样
限制性：I've never seen such a man as he is. // ......的
非限制性：As is often the case, he is absent. //
As引导的非限制性定语从句
As we all know/As is know all, he works very hard.
// 正如......
As is said/mentioned above
As is often the case
As is reported in the newapaper
As is shown in the figure
1. As VS which 的位置
As is often the case, he drives to work.
He saw the girl, as/which he had hoped.
which指整个句子时候，不可以位于句首位
2. As VS which 的语义
As i've said before, he's not suitable for this.
He has to work on Sundays, which he doesn't like(及).
as 有正如、就像之意 但which没有 不需要表正如 用 which
3. As VS which + 不同的谓语
He married her, as/which was/seemed natural.
He saw the girl, which delighted him.
1)关系代词做主语
2)系动词是两者皆可 行为动词 只能使用 which
He saw the gril， as/which he had hoped.
4.As引导的限制性定语从句
It's not such a good job as she expected
He is such a strang person as on one can understand
1)当先行词被such修饰时引导的定语从句
2)定语从句缺成分
They talked in such simple English as children could understand. // 引导定语从句 as和that/which一样, 只不过有such修饰 缺少宾语 没有任何语义
They talked in such simple English that children could understand it.// 状语从句 如此..........一致 结果状语从句
// 如何区分状语从句和定语从句
These houses are sold at such a low price as people expected(及物).
He shut the door with such a force that the glass broke(不及物).
As 引导的限制定语从句
We do the same work as they do
He is reding the same book as I did yesterday.
This is the same bag as I lost yesterday.// 就是 只有一个包
This is the same bag that i lost yesterday.// 和我昨天丢的宝一样，不是同一个包, 两个东西
as VS which
such.....as as is reported
the same.... as 代替整个句子