关系代词as与which的用法区别

关系代词as与which的用法区别

■as 和which的相同点

(1) as 和which都可引导非限制性定语从句，放在主句之后；在非限制性定语从

句中充当从句的主语、宾语或表语。如：

Tom has found a good job, as / which we all hope. 汤姆找到了一件好工作，这正是我们大家所希望的。

(2) as 和which都可代表整个句子的内容或主句中的某一成分。如：

His mother is ill, which makes him very sad. 他母亲病了，这件事情使他很难过。He has made great progress, as / which makes us very happy. 他进步了，这使得我们很高兴。

以上两句中的as / which都指前面整个句子的内容。

Though he has lots of money, he still rides his old bike, which was bought ten years ago. 尽管他很有钱，但是他还骑着他的旧单车，这单车是十年前买的。

There you can meet many writers as you have ever read in books. 在那里，你可见到你在书中所读过的很多作家。

■as与which的区别

(1) 当先行词前面有so + adj. + a / such + (a) + adj. , the same等词修饰时，引导词只能用as，而不用which。如：

She is so nice a girl as we all like. 她是个我们大家都喜欢的如此好的女孩。

It is such an interesting book as we all want to read. 它是本我们大家都想读的有趣的书。

上面两句中的as就不能用which替换。

(2) as 在从句中常作宾语；作主语时，从句的谓语动词常为系动词，即：系表结构或被动结构。如：

As you expected, he turned up on time. 正如你所愿，他按时到了。

As is said above, he has conquered the difficulty. 正如上面所说，他征服了困难。

(3) 当非限制性定语从句放到主句的前面时，引导词只能用as，而不用which。如：

As is planned, we got there before eight. 正如计划，我们再把店前到达了那儿。(4) As引导的非限制性定语从句指表示积极的意义，与主句是顺理成章的关系，绝不能与之矛盾。若非限制性定语从句表示一种消极的意义，则只用which。如：He has succeeded in his career, as / which we all hope. 他在事业中成功了，这正是

我们大家所希望的。

Her grandma died last week, which made her very sad. 她的奶奶逝世了，这使得她很悲伤。

(5) 当非限制性定语从句的引导词前面有介词时，只能用which, 而不可用as。如：

He has a new computer, for which he paid nearly ten thousand yuan. 他有一台新电脑，这台电脑花了他将近一万元。

关系代词as与which的用法区别

一、引导限制性定语从句

用在 such, same, as 等之后，引导限制性定语从句。如：

I live in the same place as Tom does. 我和汤姆住在同处。

He’s not such a fool as he looks. 他并不像看上去的那样愚蠢。

He smokes as expensive a cigarette as he can afford. 他抽一种他买得起的最贵的烟。

二、引导非限制性定语从句

(2) 单独用作关系代词，引导非限制性定语从句，可放在主句之前、之后或中间，且主从句之间一般要用逗号隔开。如：

As was expected, he succeeded at last. 正如我们所料，他终于成功了。

I had coffee after dinner, as is my usual practice. 我饭后喝咖啡，这是我的习惯。

Freddie, as might be expected, was attending the conference. 弗雷迪在参加会议，这是可以预料到的。

三、as与which的用法区别

① 引导限制性定语从句的区别：as用作关系代词引导限制性定语从句时，它通常只用于 such, same, as 等之后，而which 用作关系代词引导限制性定语从句时，则用于除 such, same, as 之外的其他结构。

② 引导非限制性定语从句的区别：which引导非限制性定语从句时，通常只能位于主句后，而as引导的非限制性定语从句位于主句之前、之后或中间。

根据从句谓语动词的特点来看，as在定语从句中作主语时，从句谓语通常要有be或别的系动词，但which不受此限制。如：

Li Ming was late, which (=and this) made Mr. Zhang very angry. 李明迟到了，这件事使张先生非常生气。（不可用as)

根据句意的逻辑性来看，as引导的定语从句只表示一个众所周知或意料之中的事，但which不受此限制。如：

He married her, as [which] was natural. 他和她结婚了，这是很自然的。

He married her, which was unexpected. 他和她结婚了，这是出乎意料的。（不可用as）