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(jié)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(nèi)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。
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(gòu)成“介詞＋關系代詞” 結(jié)構(gòu)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．a(chǎn)s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(jié)構(gòu)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(nèi)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?！?br />
(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(zhì)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.
