定語從句易錯點
知識
定語從句在句中起到形容詞的作用，是高考熱點。學生對which和that的使用經常混淆。下麵把定語從句中關係詞使用的特殊情況進行歸納。
限製性定語從句
1. 當先行詞在主句中作表語，而且關係代詞也在從句中作表語時，關係代詞常常用that。
Lianyungang is _disibledevent= for which） he was absent？
8. 英語中有幾個詞，像point， case， stage， situation， degree作先行詞，大體表示“地步，境地，情況”，並且它在定語從句中既不作主語，也不作賓語的情況下，關係詞常用where。
He has reached a point where he has to make a decision himself. 而occasion 則常常與when連用。
The occasion arises when he can go abroad to study.
非限製性定語從句
1. 在非限製性定語從句中，即使先行詞在定語從句中作賓語，關係詞也不能省略。
He has a close friend， who works as a doctor.
His home is near the museum， which we visited last week.
2. 在非限製性定語從句中，當表示先行詞的一部分時，也可用名詞/代詞+ of + which （whom）來表示。
I have some friends， several of whom are business men.
或者I have some friends， of whom several are business men.
There are about 140 kinds of snakes in Australia， most of which are not dangerous.
或者There are about 140 kinds of snakes in Australia， of which most are not dangerous.
3. 關係代詞as、which引導非限製性定語從句的區別
（1） as和which都可以替代主句的整個內容（which還可以替代一個詞），as引導的非限製性定語從句即可放在主句前，又可在主句後，有時還可以插入主句中，而which引導的非限製性定語從句一般置於主句之後。
By serving others， a person focus on someone other than himself or herself， which can be very eye-opening and rewording.
A. who B. which C. what D. that
Many animals sleep a lot when young， but sleep much less when they get older， just as is the case with human being.
A. as B. which C. what D. it
（2） as引導的非限製性定語從句的內容與主句往往是相符的，一致的，常常是肯定的，所以as常與以下關係詞連用：as is often the case， as is said， as is reported， as is mentioned above， as is known等，而which引導的非限製性定語從句與主句內容常常是不相符的，不一致的，否定的。
As you know， the earth travels around the sun.
He came late， which is unexpected.
（3）當非限製性定語從句句型為賓語補足語結構時，常常用which引導。
He was late， which made his teacher surprised.