1．who,whom和whose引導的定語從句
(1)who或whom均可指代人， 但who在從句中作主語或賓語， whom在從句中作賓語； 兩者在引導限制性定語從句時可用that替換。 作主語時， who/that不可省略； 作賓語時， whom/who/that可以省略。
◆I’ve become good friends with several of the students in my school who/whom/that I met in the English speech contest last year.
我與好幾位去年在
英語演講比賽中結識的同校同學成了好朋友。
◆I have many friends to whom I’m going to send post cards. 我有很多打算寄賀卡給他們的朋友。
◆The person I want to talk about with you is Tu Youyou, the one who won the Nobel Prize in Physiology or Medicine in 2015.
我想與你討論的人是屠呦呦，2015年獲得諾貝爾生理學或醫(yī)學獎的人。
(2)whose表所屬關系， 一般指人，也可指物， 在從句中作定語。 指物時相當于of which; 指人時相當于of whom。
◆The school shop, whose customers are mainly students, is closed for the holidays.
這家校內商店的主要顧客是學生， 放假時商店關門。
關系代詞在定語從句中作主語時，從句謂語動詞的人稱和數(shù)要和先行詞保持一致。
◆Tom is the only one of the engineers who has come up with the solution.
湯姆是想出解決方法的唯一工程師?！?br />
2．that,which引導的定語從句
(1)which指物， 在從句中可以作主語、賓語，也可作定語，作賓語時可以省略。that指人或物均可， 在從句中可以作主語、賓語、表語， 作賓語時可以省略。
◆She showed the visitors around the museum that/which had been constructed three years before.
她帶著這些游客參觀了那座三年前建造的博物館。
(2)限制性定語從句中， 關系代詞只用that不用which的情況：
①先行詞為不定代詞anything, nothing, something, everything, all, some, none, little, few, the one等時。
◆I refuse to accept the blame for something that was someone else’s fault.
我拒絕接受因別人的錯誤而對我進行的指責。
②先行詞是形容詞最高級或序數(shù)詞， 或先行詞前有形容詞最高級或序數(shù)詞修飾時。
◆The first place that they visited in Guilin was Elephant Trunk Hill.
他們在桂林參觀的第一個地方是象鼻山。
③先行詞被the only, the very, the last, the same, any, every, each, few, little, no, some，all等修飾時。
◆The only part of the meal that I really liked was the dessert. 這頓飯只有甜點是我真正愛吃的。
④先行詞中既有表示人又有表示物的名詞時。
◆They will never forget the things and persons that they’ve seen or heard of during their long journey.
他們將永遠不會忘記在他們的長途旅行中見到或聽說過的人和事。
(3)關系詞只用which而不用that的情況：
①關系詞引導非限制性定語從句時。
◆The boy was away from home for a week, which worried his parents very much.
這個男孩離家一個星期了，這使他父母很擔心。
②當從句中的介詞提前， 構成“介詞＋關系代詞” 結構時。
◆We live in an age in which more information is available with greater ease than ever before.
我們生活在一個信息比以前更容易獲得的時代。
3．as引導的定語從句
(1)as可以引導限制性定語從句，常用于“so/such/the same＋先行詞＋as…”結構中。
◆Such machines as are used in our workshop are made in China. 像在我們車間使用的這種機器是中國制造的。
which引導定語從句代指前面整句話內容時只能位于主句之后。
◆(安徽高考)Mo Yan was awarded the Nobel Prize for Literature in 2012, which made one of the Chinese people’s long held dreams come true.
莫言被授予2012年諾貝爾文學獎，這使中國人長久以來擁有的夢想之一變成現(xiàn)實。
(2)as也可以引導非限制性定語從句， 定語從句說明整個句子， 可放在主句之前、之中或之后。常用的這種類似插入語的句式有：as the saying goes, as is said above, as is mentioned above, as often happens, as is often the case, as is reported in the newspaper等。
◆She has been absent for the meeting again, as is expected. 她又缺席會議了，這在預料之中。
[典例] (2015·全國卷Ⅰ語法填空)I’d skipped nearby Guilin, a dream place for tourists seeking the limestone mountain tops and dark waters of the Li River____________are pictured by artists in so many Chinese paintings.
that/which 解析： 先行詞為waters，且引導詞在從句中作主語，故填that/which。
單句語法填空
1．(2015·陜西高考)A salesman ____________ is not punctual may not make a sale if he arrives late for an appointment.
2．(全國卷Ⅰ)Maybe you have a habit ____________is driving your family crazy.
3．(2017·福建龍巖質檢)Tibet is such a place____________ all the people across the world are dreaming of visiting.
4．(2016·江蘇高考單項填空)Many young people, most of ____________ were well educated, headed for remote regions to chase their dreams.
5．(2015·四川高考單項填空)The books on the desk，____________ covers are shiny，are prizes for us.
