定語從句中,一般的從句關(guān)系代詞是which、who、whom、that、 whose,其代替主句中的人或物,在從句中做主語、賓語或定語.而學生在學習過程中,常會遇到as作為關(guān)系代詞出現(xiàn),做起題來,無從下手,就此筆者對as作為關(guān)系代詞引導(dǎo)定語從句的情況做一歸納,以供參考.
一、as引導(dǎo)限制性定語從句
主要結(jié)構(gòu)有：
the same…as
as…as
such…as
so…as
主句中出現(xiàn)the same,as,such,so修飾先行詞,需選擇as做關(guān)系代詞在定語從句中做主語或賓語.
1.It’s the same person as we wanted to find yesterday .
我們昨天要找的是同一個人.
2.Such girls as he knows are good at English .
他所認識的女孩都擅長英語.
3.Do you have such books as we like
你有我們喜歡那種書嗎?
4.She will marry as healthy a man as she can find .
她將嫁給她能找到的任何一個有錢人.
5.There is so warm a house as we want to live in .
這里有如此暖和的房子,我們都想住在里面.
6.He has so difficult a problem ,as none of us can solve .
他有如此難的一個問題,我們沒有人能解決.
二、引導(dǎo)非限制性定語從句
⑴ as引導(dǎo)非限制性定語從句,指代整個主句內(nèi)容,從句可置于句首,句中或句尾
1． As everyone knows ,China is a beautiful country with a long history .
每個人都知道,中國是一個有著悠久歷史的美麗國家.
2． The earth ,as we know ,moves round the sun .
地球,我們都知道,圍著太陽轉(zhuǎn).
3． Tom works hard and is willing to help others,as we all know.
湯母工作努力,并且樂于助人,這一點我們都知道.
⑵ 非限制性定語從句中的謂語為被動式時,常用as做主語
be said/known/announced/reported/mentioned/expected/discussed
1.Grammar ,as has been said before,is not a set of dead rules.
語法,就像以前所說,不是一套死規(guī)則.
2.As is known to all ,TaiWan is part of China .
⑶ as引導(dǎo)非限制性定語從句,有“如,似,正像”的含義,因此,下列句式多用as
as has been said above
如上所說
as anybody can see
正像每個人所看到的那樣
as we had expected
正如我們所預(yù)料的那樣
1.Things are not always as they appear.
事情并不一直像他們表面那樣.
2.The boy has as much progress as we had expected.
正像我們所預(yù)料的那樣,這個男孩取得了大的進步.
由as,which 引導(dǎo)的非限定性定語從句,as和which可代整個主句,相當于and this或and that.As一般放在句首,which在句中.
As we know,smoking is harmful to one';s health.
The sun heats the earth,which is very important to us.
as 和which在引導(dǎo)非限制性定語從句時,這兩個關(guān)系代詞都指主句所表達的整個意思,且在定語從句中都可以作主語和賓語.但不同之處主要有兩點：
(1） as 引導(dǎo)的定語從句可置于句首,而which不可.
(2） as 代表前面的整個主句并在從句中作主語時,從句中的謂語必須是系動詞；若為行為動詞,則從句中的關(guān)系代詞只能用which..