Relative clause mệnh đề quan hệ
Peter is intelligent. He is my friend
Peter who is my friend is intelligent.
Trạng từ quan hệ Where
Where: ở đâu: dùng để thay thế cho N chỉ địa điểm (city, house, shop), there.
Eg: I was born in Hanoi. I live there.
I was born in Hanoi where I live .
Eg; The house where I lived as a child has been pulled down now.
The house has been pulled down now. I lived as a child in that house..

Trạng từ quan hệ when
When: khi, lúc: dùng thay thế cho thời gian (day,month, week…), then
Eg; I will never forget that day. I met her on that day.
I will never forget that day when I met her
Trạng từ quan hệ why
Why: tại sao; dùng thay thế cho lí do (the reason)
Eg I don’t know the reason. He didn’t do like himself.
I don’t know…………………………………….
Ví dụ
I am talking to the man. He is in red.
I am talking to the man who is in red.
I am talking to who is in red.
I am talking to the man in red.


That có thể thay thế cho who, whom, which trong các trường hợp sau
Trong câu có:
So sánh nhất: the biggest, the most…
Đại từ bất định (some, any, no…)
Số thứ tự: the first, the last…
eg
1.This is my uncle. He is the most intelligent in this company.
This……………………………………………...
This is my uncle who is the most ………….
This is my uncle that is the most intelligent in this company
Defining relative clause: mệnh đề quan hệ xác định
Mệnh đề QHXĐ là mệnh đề dùng để xác định N đứng trước nó. Mệnh đề XĐ là mệnh đề cần thiết cho ý nghĩa của câu, thiếu nó câu sẽ không đủ rõ nghĩa.
Eg: the man who robbed you has been arrested.
The book that you lent me was very interresting.
Note! Chú ý

Trong MĐQHXĐ chúng ta có thể lược bỏ các ĐTQH làm tân ngữ: whom, that
Eg: the man robbed you has been arrested.
The book you lent me was very interresting.
Non defining relative clause
mệnh đề quan hệ không xác định
MĐQHKXĐ là mệnh đề dùng để giải thích thêm thông tincủa một người ,vật hoặc sự việc đã được xác định. Mệnh đề này có thể có hoặc không vì ko có nó thì câu vẫn đủ nghĩa. Nó được phân biệt bằng dấu , hoặc dấu -.

Eg That man, who lives in the next door, looks lonely.
The book Jane Eyre, which I was reading, is really good.
Mệnh đề rút gọn
reduced form of relative clause.
I, Mệnh đề rút gọn bằng cụm phân từ hiện tại (Ving) khi:
Động từ trong mệnh đề ở thì tiếp diễn và dạng chủ động.
Eg: that man, who is sitting next to Mandy, is my uncle.
→ That man, sitting next to Mandy, is my uncle.


b. Động từ trong mệnh đề chỉ ước muốn, mong đợi, hy vọng…
Eg Fans who hope to buy tickets have been queing all night.
→ Fans hoping to buy tickets have been queing all night.

c. V trong MĐQH diễn đạt hành động hoặc sự việc có tính thường xuyên,lâu dài thành thói quen.
Eg1 The road that joints the two villages is very narrow.
→ The road joining the two villages is very narrow
II, Mệnh đề rút gọn bằng cụm phân từ hai (Vp2)
Nếu V trong câu MĐQH ở thể bị động ta dùng Vp2 thay cho ĐTQH và V.
Eg The books which were written by ToHoai are interesting.
→ The books written by ToHoai are interesting.
Eg2 The boy who was injured in the accident was taken to the hospital.
→ The boy injured in the accident was taken to the hospital
III, Mệnh đề quan hệ rút gọn dùng TO INFINITIVE khi
a. To infinitve đứng sau từ chỉ số thứ tự, so sánh nhất(next ,last, only, the second, the biggest…).
Eg The captain was the last man who left the ship.
→ The captain was the last man to leave the ship.
Eg2 The guest on our show is the youngest golfer who won the Open.
The guest on our show is the youngest golfer to win the Open.
b.To infinitive được dùng khi diễn đạt mục đích hoặc sự cho phép.
Eg1 The children need a big yard which they can play in.
The children need a big yard to play in.
Eg2 Here is the form that you must fill in.
Here is the form for you to fill.
Eg3 I wish we had a garden that our children could play in.
I wish we had a garden for our children to play in.

Note chú ý
To infinitive có hai dạng:
To infinitive hoặc for + O+ To infinitive.
Giới từ trong MĐQH
Trong văn phong trang trọng, giới từ đứng trước ĐTQH : WHOM và WHICH.
Eg1 the man to whom my mother is talking is my form teacher.
Eg2 The shop to which we normal go is closed.
2. Trong lối nói thân mật, giới từ đứng sau V trong MĐQH.
Eg1 The picture that she was looking at was famous.
Mệnh đề tính ngữ
1. When: khi nào
Dùng để thay thế cho N chỉ thời gian.
(year,day,time,centery…)
Trong mệnh đề tính ngữ có giới từ thì when được thay bằng which và giới từ đặt trước which.
Eg I never forget the day. I met you on that day.
I never forget the day on which I met you.

2. where: mệnh đề tính ngữ dùng để thay thế cho N chỉ địa điểm.
(city, country, room…)
Trong mệnh đề tính ngữ có giới từ thì when được thay bằng which và giới từ đặt trước which.
Eg; The building is very old. He lives there.
The building where he lives is old.
Eg The building is very old. He lives in that building.
The building in which he lives is old.
Ex
.
1. she is the most intelligent woman. I have ever met this woman.
2. this doctor is famous. You visit him yesterday.
3. Do you know the music? It is being played on the radio.
I. use a relative clause to combine each pair of sentence
4. The police want to know the hotel. Mr Foster stayed there for 2 days ago.
5. These children are orphans. She is taking care of these children.
6. the two young men are not good people. You are acquainted with them.
7. He doesn’t want to sell the house. He was born in this house.
8. The airport is the most modern one. We are going o arrive at this airport.
9. we enjoy the city. We spent our vacation in this city.
10. I looked at the moon. It was very bright that evening.
11. the man is my father. I respect this man most.
12. please post the letter. I wrote it this evening.
13.the man is my father. I respect his opinion most.
14. The building is the church. Its tower can be seen from far.
15. Mary and May are twins. You met them last Sunday.
II. Using Ving to connect the sentences.

The boy who spoke to John is my brother.
The boy speaking to john is my brother.
2. Do you know the woman who is coming toward us?
Do you….
3. The people who are waiting for the bus in the rain are getting wet.
….
II. Using Ving to connect the sentences.(4)
4.The scientists who are researching the cause of cancer are making progress.
5.My grandmother, who is old and sick, never go out of the house.
6. The woman who lived here before us is a romantic novelist.
7. Ann is the girl who is responsible for the mistake.
8. Ian Bolivar, who was a great student, led the fight for indipendent in 19th.
III. Using To+ V
1. David was the only person who offerred the job.
David….
2. There is a big yard that your children can play in.
There …
3.Elma is the most famous actress who will appear on stage here.
Elma …
4. he was the second man who was killed in this way.
He…
Using To+ V
5. He offered his help . Nobody can did.
He…