考研英語真題：賓語從句的限定性和非限定性代表什么意思呢？

同學(xué)，是定語從句的限定性和非限定性襖。

一、定語從句分為限制性和非限制性兩種。限制性定語從句不可缺少先行詞，去掉它主句意思往往就不明確了，它與主句之間通常不用逗號分開;非限制性定語從句是對先行詞的附加說明，去掉它也不會影響主句的意思。如:Do you know the professor who is speaking at the meeting? (限制性定語從句) 

English is an important subject,which every student should study well. (非限制性定語從句)

二、 限制性定語從句的先行詞往往是某一個詞, 但非限制性定語從句的先行詞可以是一個詞， 也可以是句子的一部分,甚至是整個主句，此時非限制性定語從句一般由which或as引導(dǎo)， as引導(dǎo)非限制性定語從句常用在as is said /known / expected / mentioned / reported / announced等結(jié)構(gòu)中。如:He has passed the college entrance examination, which makes his parents quite happy.As is known to everybody, the moon travels round the earth once every month.

三、關(guān)系詞的使用情況有所不同1. that不可引導(dǎo)非限制性定語從句。如:Her father gave her a computer for her birthday, which pleased her a lot.2. why 不用在非限制性定語從句中，需用for which代替。如: | told them the reason, for which I didn't attend the party last week.3.關(guān)系代詞替代情況不同關(guān)系代詞whom在限制性定語從句中作賓語時可用who代替whom,但whom在非限制性定語從句中作賓語時不可用who代替。如:This is the girl whom who | have been in love with for six years.The young man had a new girl friend, whom he wanted to show all his love for.4.關(guān)系代詞省略情況不同關(guān)系代詞在限制性定語從句中作賓語時可以省略;非限制性定語從句的所有關(guān)系代詞均不可省略。如:She is the new student whom / who / that | want to introduce to you.All the books there, which have beautiful pictures in them, were written by him.