介詞加關系代詞引導的定語從句主要用于正式文體。直接用于介詞后作賓語的關系代詞which不能換成that，直接用于介詞后作賓語的關系代詞whom不能換成who。

“介詞+關系代詞”引導定語從句

1.由“介詞+關系代詞”引導的定語從句主要用于正式文體，在非正式文體中通常將介詞放至句末。

如：This is the man to whom I referred.我指的就是這個人。

This is the man (whom) I referred to.我指的就是這個人。

2.直接用于介詞后作賓語的關系代詞which不能換成that，直接用于介詞后作賓語的關系代詞whom不能換成who。但若介詞用于句末，則用作賓語的which,whom也可換成that,who，或者省略。

如：這是一個我們討論了許多的問題。This is a subject about which we have talked a lot.(which不能換成that，也不能省略)

This is a subject which we have talked about a lot.這是一個我們討論了許多的問題。(which可以換成that，也可以省略)

3.關系副詞when,where,why根據(jù)情況有時可換成“介詞+關系代詞which”。

如：That is the day when[=on which]he was born.那就是他出生的日子。

That is the house where[=in which]he lived.那就是他住過的房子。

That is the reason why[=for which]he must apologize.那就是他必須道歉的原因。

4.在很正式的文體中，“介詞+關系代詞”引導的定語從句可緊縮成“介詞+關系代詞+不定式”結構。如：在那兒孩子們有個玩耍的花園。正：There the children had a garden in which to play.(很正式)

正：There the children had a garden in which they could play.(較正式)

正：There the children had a garden to play in.(較口語化)

注：這類“介詞+關系代詞+不定式”結構中的介詞不能沒有，也不能放在句末。如不能說There the children had a garden which to play in.

“介詞+關系代詞”的結構

1.“介詞+ which”在關系分句中分別可作時間、地點和原因狀語，代替相應的關系副詞when, where和why。如：

①I still remember the day on which (=when) I first came to school.我仍然記得初來學校的那一天。

②The factory in which (= where) I work is a large one.我工作的工廠是一個大廠子。

2.“介詞+ which（指物）/whom（指人）”在關系分句中作地點狀語，表示存在關系，關系分句主謂常須倒裝。如：

①They arrived at a farm house, in front of which sat a small boy.他們來到一處農(nóng)舍，前邊坐著一個小男孩。

②I saw a man, on the head of whom stood a bird.我看見一個人，他的頭上有一只鳥。

3.“不定代詞或數(shù)詞+ of + which（指物）/whom（指人）”在關系分句中作主語，說明整體中的一部分。如：

①China has a lot of islands, one of which is Diaoyu.中國有許多島嶼，其中之一是釣魚島。

②There are a lot of students here, none of whom like the film.這里有許多學生，他們之中無人喜歡這部電影。

4.“介詞+ which（指物）/whom（指人）”在關系分句中作目的、方式或地點狀語。如：

①Could you tell me for whom you’ve bought this coat? 你能告訴我這件衣服是給誰買的嗎？

②The man, from whom I learned the news,is an engineer.這人是一位工程師，我是從他那里得到這個消息的。

5.“介詞+ which（指物）/whom（指人）”用于被動結構的關系分句中，作狀語，說明動作的執(zhí)行者。如：

①The wolf by which the sheep was killed was shot.傷害羊的那只狼被打死了。

②The man by whom the wolf was shot was a good hunter.打死狼的那人是一個好獵手。

6.“名詞+of which”代替“whose+名詞”在關系分句中作定語。如：

①I saw some trees,the leaves of which (= whose leaves ) were black with disease.我看見一些樹，它們的葉子因害病而發(fā)黑。

②He mentioned a book, the title of which (= whose title) I’ve forgotten.他提到一本書，書名我忘了。

7.“介詞+which（指物）/whose（指人）”修飾后邊的名詞。如：

①It rained all night and all day, during which time the ship broke into pieces.雨下了一天一夜，就在這期間輪船撞碎了。

②The driver was the man from whose room she had stolen the maps.司機就是那個男人，她從他的房間偷走地圖。

8.“介詞+which+不定式”。此種用法多見于正文體中，相當于一個帶有主語和謂語的定語從句。如：

She had only 1.87 with which to buy (=she could buy) Jim,her husband,a present.她只有一元八角七分錢，用這些錢她給丈夫吉姆買一件禮物。