定语从句分为限制性定语和非限制性定语从句,两者都是英语语法学习中的重点和难点,非限制性定语从句在句中主要起补充说明作用,缺少也不会影响全句的理解,这次小编就为大家来讲解一下由which和as引导的非限制性定语从句的区别,一起学起来吧!

1)位置上,as可放在句首、句末,也可插入主句中;which一般放在主句之后(有时也可用as):

    As we all know, reading is very important.

    Reading is very important, which we have already known when we were very young.

(2)意义上,as有正如、按照、正像之意,一般用在肯定句中;which可用于含肯、否定意义的句子中:

    He failed in the exam again, as was expected.

    He failed in the exam again, which was unexpected.

 (3)当定语从句所修饰的主句内容是谓语动词的对象时,常用as,如:

   She finally stopped crying, as we had expected.

 

(4)当关系代词代表主句引起的结果,又做主谓宾补(SVOC)结构中的主语时,多用which:

    He passed the exam, which made him delighted.

(5)在从句中作介词宾语时,用which,如:

    They went into a room, in which the muder happened.

(6)在从句中代表主句中的谓语的整个概念时,常用which,如:

    She can both sing and dance, which I cannot.

好了以上就是为大家带来的which和as引导的非限制性定语从句的区别了,希望大家在学习中能够仔细辨析这些区别,最终达到能轻松分辨不同句式,对各类句型都应用自如的水平。