as引导的定语从句 1. as用作关系代词和关系副词引导限制性定语从句，并在从句中作主语、宾语、状语或表语，构成the same as, suchas, soas, asas等结构，也就是说，先行词之前一旦出现same, such, so, as这些词时，而先行词的后面又跟着一个从句，这时就要考虑是不是要用as作为关系词来连接这个词和这个句子。 例如： No period in history has had as many important changes as have taken place in the past century. (as 作主语) It is so easy a book as every schoolboy can read. (as作宾语) A wise man seldom talks about such things as he doesn’t understand.(as作宾语) I shall do it in the same way as you did.(as作状语) Her skin is as white as snow is. (as作表语) 注意：(1)关系代词as在限制性定语从句时，在从句里做宾语时，绝不能省略。为什么我要让大家注意呢? 因为大家会联想到that和which引导定语从句，做从句里的宾语时可以省略。但是，大家要记住，我们今天讲的是as引导的定语从句，as在定语从句里做宾语时，是绝不能省略的。没有为什么，这就是语言的习惯。举几个例子大家看看。 Nowadays, women can receive the same pay as men can receive. 这句话里面，as就绝不能省略。 而这句话 Nowadays, women can receive the same pay that men can receive. 里面的that就可以省略。 所以，这句话也可以说成 Nowadays, women can receive the same pay men can receive. (2)刚说过的这个例子大家可能已经注意到the same as 和the same that这两个结构了。当先行 词被 the same 所修饰时，关系词既可以用 as，也可以用 that，那么这两者又有什么区别呢?在表示具体事物时，有时两者有一定的区别。一般说来，表示同一种类多用 as，表示同一事物多用 that，来看个例子： This is the same instrument as I used yesterday. 这台仪器跟我昨天用过的那台一样。 This is the same instrument that I used yesterday. 这就是我昨天用过的那台仪器。 大家看这两句话的意思已经明白它们的区别了吧?as表示的是一样的，同一种类的事物，但会不 会就是那个他用过的呢?不一定。而that则完完全全地是我用过的'。 但是表示抽象概念时，同种类和同一事物是没有绝对区别的，所以两个词可换用，请看例句 I have the same opinion as / that you have. 2. as引导非限制性定语从句。as在定语从句中作主语、表语或宾语。as代指整个主句，而as引导的这个定 语从句是用来补充说明整个主句的，可以放在主句之前或者之后。 例如： As we all know, he studies very hard.(as代整个句子，作宾语) 也可说 He studies very hard, as we all know. As is known to all, he is the best student in our class.(as代整个句子，作主语) 也可说 He is the best student in our class, as is known to all. 一些常见的句式有：as is said above, 正如/就像上面所说的， as is already mentioned above, 正如/就像刚才 已经提到的，as is known to all, 正如/就像大家都知道的，as is reported in the newspaper, 正如报纸上报道的那样。大家发现特点没有啊?as在句子里面的意思是“正如”“就像” 注意：(1)关系代词which和as在引导非限制性定语从句时是有区别的，它们的区别就是是：which引导的非 限制性定语从句，绝不能放在句首，而as则可以;就像我们刚看到的例子一样， He studies very hard, as we all know. 也可说As we all know, he studies very hard. 而要是换成which的话，这句话只能说成是 He studies very hard, which we all know. 在句中时，as有“正如”“就像”之意，而which则没有此意。现在请大家看这两句话 He studies very hard, 本文来源：https://www.wddqw.com/doc/e42715598d9951e79b89680203d8ce2f006665d2.html