定語從句關係代詞句子
關係詞通常有下列三個作用：1)引導定語從句;2)代替先行詞;3)在定語從句中擔當一個成分。
關係代詞有that，which，who，whom，whose，as等;
一：關係代詞的用法 關係代詞 指代對象及在從句中所作的成分
使用要點
that
即指人又指物;作主語或賓語(作賓語時可省略)
只用於限制性定語從句中，介詞後面不能跟that。 當代替物時，可以與which通用。
Yesterday Emily was wearing the new dress that I gave her.
昨天艾米麗穿了我送給她的新衣服。
I have a friend that likes listening to classical music我有個朋友喜歡聽古典音樂。
which
指物;作主語或賓語(作賓語時可省略)
在非限定性定語從句中，只宜用which,不能用that.在限定性定語從句中，可用在介詞之後。
My parents live in a house which is more than 100 years old
我的父母住在一座具有100多年曆史的`房子裏
who,whom
指人;作主語或賓語(whom常可省略) 先行詞必須爲人。Who可代替在從句中擔任賓語的whom,若前有介詞，須用whom
A couch potato is a person who spends a lot of time watching TV. “A couch potato”指那種成天沉湎於電視中的人。
The student(whom)I taught two years ago has joined the army.
我兩年前教的那個學生已經參軍了。
whose 既指人又指物;作定語 是代詞的所有格， 代物時，相當於of which。
The room whose window faces south is mine. 那個窗戶朝南的房間是我的。
注意：whose指物時，常用of which結構來代替。如：
The classroom whose door is broken will soon be repaired.
=The classroom the door of which is broken will soon be repaired.
指人，在從句中做主語
(1)The boys who are playing football are from Class One.
(2)Yesterday I helped an old man who lost his way.
2. whom指人，在定語從句中充當賓語，常可省略。
(1) Mr. Liu is the person (whom) you talked about.
注意：關係代詞whom在口語和非正式語體中常用who代替，可省略。
(3) The man who/whom you met just now is my friend.
3. which指物，在定語從句中做主語或者賓語，做賓語時可省略
(1) Football is a game which is liked by most boys. ( which 在句子中做主語)
(2) This is the pen (which) he bought yesterday. ( which 在句子中做賓語)
4. that指人時，相當於who或者whom;指物時，相當於which。
在賓語從句中做主語或者賓語，做賓語時可省略。
(5) The people that/who come to visit the city are all here. (在句子中做主語)
(6) Where is the man that/whom I saw this morning? (在句子中做賓語)
5. whose通常指人，也可指物，在定語從句中做定語
(1) He has a friend whose father is a doctor.
(2) I lived in a house whose roof has fallen in.
whose指物時，常用以下結構來代替
(3)The classroom whose door is broken will soon be repaired.
=The classroom the door of which is broken will soon be repaired.
(5)Do you like the book whose color is yellow?
=Do you like the book the color of which is yellow?
