2. 先行詞指物，用關系代詞which

　　同學們先把下面這兩句話合并成一句話：

　　The book is interesting.

　　I bought it yesterday.

　　The book which I bought yesterday is interesting.(關系詞 which 就是指代的書，在定語從句中作bought 的賓語，所以原句中買的賓語it 要去掉)

　　我們來做拆句練習：

　　如：The building which stands near the train station is a supermarket.位于火車站附近的那座大樓是一家超市。(which替代的物，作從句的主語)

　　The building is a supermarket.

　　The building stands near the train station.( which指代的內(nèi)容還原)

　　The computer which I wanted to buy was sold out.我想買的那種計算機賣完了。(which替代的物，作從句的賓語)

　　She was fond of dancing, which her brother never was.她喜愛跳舞，她弟弟不喜愛.( which替代的物，作從句的表語)

　　注：當關系代詞接跟介詞，作介詞賓語，只能用which指物。

　　如：This is the house in which we lived last year.這就是我們?nèi)ツ曜〉姆孔印?which作介詞in的賓語，不可以用that替換)

　　4.that可以指人，也可以指代物

　　that可以指人，也可以指代物,不能用在非限定性定語從句中，也不能用在介詞后面。

　　如：The man that is speaking at the meeting is a famous scientist.會上講話的那個人是一位著名的科學家。(that指代人，作從句的主語)

　　Is this the photo that you took last summer? 這是你去年夏天照的相片嗎?(that指代物，作從句的賓語)

　　在下面幾種情況下，必須用that引導定語從句：

　　1) 先行詞是不定代詞all, few, little, much, everything, anything等

　　如：Is there anything that you want to buy in the shop? 你在商店里有什么東西要買嗎?

　　再如：2001年第33小題：

　　All that is needed is a continuous supply of fuel.

　　2) 先行詞被序數(shù)詞或形容詞最高級所修飾，或本身是序數(shù)詞，形容詞最高級

　　如：This is the best movie that I have ever seen.這是我看到過的最好的一部電影。

　　3) 先行詞被all, any, every, each, few, little等修飾時

　　如：I have read all the books that you gave me.我讀了你給我的所有的書。

　　4) 先行詞被the only, the very, the same, the last修飾時

　　如：He is the only person that I want to talk to.他是我要談話的那個人。

　　5) 當并列的兩個先行詞分別表示人或物

　　如：They are talking about persons and things that they remembered.

　　6)在以who或which開頭的特殊疑問句時，為避免重復

　　如：Who is the girl that is crying? 正在哭泣的那個女孩是誰?

　　Which of the books that borrowed from the library is yours? 從圖書館借的哪一本書是你的?

　　7)修飾表示時間的名詞如day, time, moment等，代替when.

　　如：It happened on the day that he was born. 這件事碰巧發(fā)生在他出生的那天。

　　8)如果兩個定語從句，其中一個關系詞已經(jīng)用了which,另外一個用that

　　如：The country built up a factory which produced things that have never been seen before.這個國家建立了一個生產(chǎn)以前未曾見過的東西的工廠。