2. He who laughs last laughs best.谁笑到最后，谁笑的最好。
3. Nothing in the world is difficult for one who sets his mind to it.世上无难事，只怕有心人。
用来修饰名词或代词的词称为定语 a tall building the book on the desk anything important the girl in red 如果定语是句子，便称为定语从句。
I know the girl. The girl is in red. 两个简单句 →I know the girl who is in red. （定语从句） 被修饰的词是_______________。这个词就称为先行词。
其中连接两个句子的是______________， 称为关系词。关系词在从句中指代先行词，并在从句中充当一定的成分，观察上句，关系词在从句中充当________________。
附关系词与先行词的关系 关系词和先行词密切相关，因为关系词用来指代先行词，并且在从句中充当一定的成分。
定语从句中常用的关系词有 关系代词 who / whom 先行词表示人 which 先行词表示物 that / whose 先行词表示人或物 关系代词在从句中可充当主语，宾语或定语；
可以和介词连用的关系代词whom, which （on which, with whom, for which） 关系副词 when 表示时间 where 表示地点 why 表示原因 关系副词在从句中充当状语。
二．按关系词种类学习 1．由that引导的定语从句 一般情况下that可指人或物，可以代替who，whom和which，但不能置于介词之后。如 The man that（who）is speaking at the meeting is an advanced worker． 正在会上讲话的那个人是个先进工人。
Is this the doctor that（whom）you talked about yesterday这就是你们昨天谈论的那位医生吗 The letter that（which）I received yesterday was from my father．昨天我收到的信是我父亲寄来的。
2．由who，whom和whose引导的定语从句 who在从句中作主语,有时也可以代替whom做宾语；
whom在从句中作宾语；
whose在从句中作定语。如 This is the thief who stole my bike．这就是偷我自行车的那个贼。
He is the boy whom you wanted to find．他就是你想要找的那个男孩。
The girl whose mother is a doctor is waiting for you outside．妈妈是个医生的那个女孩在外面等你。
3．由which引导的定语从句 which指物，在从句中作主语或作谓语动词的宾语。如 The book which Mum bought me last week is very good．妈妈上周买给我的那本书很好。
The house which was built last year belongs to them. 这个去年建的房子属于他们。
4．由where，when和why引导的定语从句 where在从句中作地点状语，when在从句中作时间状语，why在从句中作原因状语。如 I will never forget the day when on which I joined the League．我永远忘不了我入团的那一天。
He will go back to the school where in which he studied next week． 下周他要回到他曾经学习过的学校。
I dont know the reason why for which he quarreled with Zhang Lin． 我不知道他同张琳吵架的原因。
三．注意点 （1）关系代词在定语从句中作宾语时，关系代词常省去。
如The play（which）I watched just now had been on twice on Channel 3. 我刚才看的那个戏剧在3频道上已上演了两次。
（2） 当定语从句中含有介词，介词放在句末时，who， that， which可省略，但介词在关系代词前时，只能用“介词which/whom”结构。
如This is the house that/ which we lived in last year. This is the house in which we lived last year. 这是我们去年居住的房子。
Please tell me the person who/ whom you borrowed the English novel from. Please tell me from whom you borrowed the English novel. 请告诉我你从谁那借的这本英文小说。
（3）关系词只能用which，而不用that 的情况 a.先行词为that，those时，用which，而不用that。例如 What’s that which is under the desk 在桌子底下的那些东西是什么 b.关系代词前有介词时，一般用which，而不用that。例如 This is the room in which he lives. 这是他居住的房间。
c.引导非限制性定语从句，用which， 而不用that。例如 The necklace, which you gave me as a present, was lost yesterday. 你送给我做礼物的项链昨天丢了。
Tom came back，which made us happy. 汤姆回来了，这使我们很高兴 He told the secret to others, which annoyed us. 他把秘密告诉了其他人，这惹怒了我们。
（4）关系词只能用who, 而不用 that 的情况。
a. 当先行词是泛指代词he，they，people或指示代词those等时，常用who。如 Hewhodoesnoworkgetsnopay. 不工作的人是没有报酬的。
Weareinneedofthosewhocanwork hard. 我们需要那些努力工作的人。
b. 不定代词one，ones，anyone等作先行词时，多用who。如 Onewhoworkswithoutcomplainiswelcomehere．那些工作没有抱怨的人在这受欢迎。
c. 在非限制性定语从句中，一般要用who，不用that。如 The man, who comes from France, helped us at last. 那个来自法国的人最终帮助了我们。
（5）关系词只能用that, 不用who或which的情况 a. 先行词被序数词或形容词最高级所修饰，或本身是序数词、形容词最高级时，只能用that，而不用which。例如 He was the first person that passed the exam. 他是第一个通过考试的人。
This is the best book that I have ever read. 这是我读过的最好的书。
b.被修饰的先行词为all, few, little, much, everything, anything, nothing, none等不定代词时，只能用that，而不用which。例如 Is there anything that you want to buy in the shop 你在商店里有什么东西要买吗 c.先行词被all, every, the only，the very，the same，the last，little，few, any, no 等词修饰时，只能用that，而不用which。例如 This is the same bike that I lost.这就是我丢的那辆自行车。
d. 先行词里同时含有人或物时，只能用that， 而不用which。例如 I can remember well the persons and some pictures that I saw in the room.我能清楚记得我在那个房间所见到的人和一些照片。
e. 以who或which引导的特殊疑问句，为避免重复，只能用that。例如 Who is the girl that is crying 正在哭泣的那个女孩是谁 （6）关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。
例如The boys who are playing football are from Class One. （7）注意定语从句中，先行词与关系代词可合成what 的用法 Please tell me what you said just now. Please tell me the words that you said just now. He showe