Chuyển đổi từ hiện tại hoàn thành sang quá khứ đơn (và ngược lại)

DẠNG 1 : ChUYỂN ĐỔI TỪ HIỆN TẠI HOÀN THÀNH SANG QUÁ
KHỨ ĐƠN ( VÀ NGƯỢC LẠI )
Dạng này có các mẫu sau đây , công thức thì không có nên mình chỉ đưa ra các ví dụ
trong đó có các chổ tô màu là những dấu hiệu để nhận dạng ra công thức.
1. This is the first time I have seen him (đây là lần đầu tôi thấy anh ta )
=>I have never seen him before. ( tôi chưa bao giờ thấy anh ta trước đây )
Mẫu này có dạng :
Đây là lần đầu tiên ... làm chuyện đó
=> ...chưa bao giờ làm chuyện đó trước đây.
The first time : lần đầu tiên
Never ...before : chưa bao giờ trước đây
2. I started / begun studying English 3 years ago. (tôi bắt đầu học TA cách đây 3
năm )
=> I have studied English for 3 years. ( tôi học TA được 3 năm )
Mẫu này có dạng :
...bắt đầu làm gì đó cách đây + khoảng thời gian
=> .. đã làm chuyện đó for + khoảng thời gian
Nếu không có ago mà có when + mệnh đề thì giử nguyên mệnh đề chỉ đổi when
thành since thôi
3. I last saw him when I was a student.( lần cuồi cùng tôi thấy anh ta là khi tôi là SV
)
=> I haven't seen him since I was a student.( tôi đã không thấy anh ta từ khi tôi là
SV )
Mẫu này có dạng :
Lần cuối cùng làm chuyện đó là khi ....
=> ..không làm chuyện đó từ khi ....
Last : lần cuối
Since : từ khi
4. The last time she went out with him was two years ago.(lần cuối cô ta đi chơi với
anh ta cách đây 2 năm )
=> She hasn't gone out with him for two years.( cô ta đã không đi chơi với anh ta đã

2 năm nay )
Tương tự mẫu 3 nhưng khác phần sau thôi
5. It's ten years since I last met him.(đã 10 năm từ khi tôi gặp anh ta lần cuối )
=> I haven't met him for ten years . ( tôi đã không gặp anh ta 10 năm rồi )
Mẫu này có dạng :
Đã ..khoảng thời gian từ khi làm gì đó lần cuối
=> ..không làm việc đó được + khoảng thời gian
6. When did you buy it ? ( bạn đã mua nó khi nào ?
=> How long have you bought ? ( bạn đã mua nó được bao lâu ? )
Mẫu này có dạng :
when : thì dùng quá khứ đơn
How long : thì dùng hiện tại hoàn thànhViết lại câu không thay đổi nghĩa:
1) This is the first time he went abroad.
=> He hasn’t……
2) She started driving 1 month ago.
=> She has……
3) We began eating when it started to rain.
=> We have……
4) I last had my hair cut when I left her.
=> I haven’t….
5) The last time she kissed me was 5 months ago.
=> She hasn’t….
6) It is a long time since we last met.
=> We haven’t…..
7) When did you have it ?
=> How long …..?
8) This is the first time I had such a delicious meal .
=> I haven’t…..
9) I haven’t seen him for 8 days.
=> The last …..

10) I haven’t taken a bath since Monday.
=> It is ….
DẠNG 2 CÁC DẠNG ĐỀ THƯỜNG GẶP VỀ TOO...TO , SO..THAT,
SUCH..THAT , ENOUGH :
1) ĐỔI TỪ SO ..THAT SANG SUCH ....THAT :
N + BE + SO + ADJ + THAT + CLAUSE
=> ĐẠI TỪ + BE ......
Cách làm :
Thêm such ( a,an) đem tính từ xuống ,đem danh từ xuống ,từ that trở đi viết lại hết
=> ĐẠI TỪ + BE SUCH ( A,AN ) ADJ + N + THAT CLAUSE
The book is so interesting that I have read it many times.
It is .....
=> It is such an interesting book that I have read it many times.
Nếu danh từ là số ít hoặc không đếm được thì không có a, an
2) ĐỔI TỪ SO ..THAT SANG TOO...TO :
Đề có dạng :
S + BE +SO + ADJ + THAT + CLAUSE
=> S + BE + TOO....
Cách làm :
Thêm tính từ vào , bỏ can't ,couldn't lấy từ động từ trở đi
Nếu chủ từ 2 câu khác nhau thì thêm phần for sb
Nếu túc từ câu sau giống chủ từ câu đầu thì bỏ túc từ đó đi
=> S + BE + TOO + adj +( FOR SB ) TO INF ...
The water is so hot that I can't drink it.
=> The water is too.....
=> The water is too hot for me to drink.
- Nếu đổi nguợc lại từ TOO...TO sang SO ..THAT thì thường sai nhất là việc quên
thêm túc từ vào và chia sai thì
3) ĐỔI TỪ TOO...TO .. SANG ENOUGH :
Đề thường có dạng :

S + BE + TOO + ADJ + TO INF......
=> S + BE NOT .....
Cách làm :
- Dùng tính từ phản nghĩa + enough
- Viết lại hết phần sau
He is too weak to run fast
=> He isn't ....
=> He isn't strong enough to run fast.
Ghi chú :Trong tất cả các cấu trúc trên nếu chổ BE là V thì ADV sẽ thay cho ADJ
Viết lại câu không thay đổi nghĩa:
1) The room is so tidy that it took us one hour to clean it.
=> It is ....
2) The man is so fool that no one took any notice of him.
=> He is ....
3) The film is so long that they can't broadcast it on one night.
=> It is .....
4) The books are so interesting that we have read them many times.
=> They are.....
5) The news was so bad that she burst into tears on hearing it.
=> It was....
6) The food was so hot that it turned my tongue.
=> It was.....
7) There is so much rain that we can't go out.
=> There is such....
8) The boy is so fat that every calls him Stuffy.
=> He is ....
9) The milk is so excellent that all the children want some more.
=> It is ....
10) The weather was so warm that they had a walk in the garden.
=> It was....

11) There were so many people in the hall that we couldn't see him.
=> There were such...
12) The match was so exciting that all the fans shouted loudly.
=> It was...
13) They drank so much coffee that they couldn't sleep all night.
=> They drunk such.....
14) Alice had so many exercises to do that she couldn't go out.
=> Alice had such.....
15) The woman was so poor that she needed everyone's help.
=> She was .....
Key
1) The room is so tidy that it took us one hour to clean it.
=> It is such a tidy room that it took us one hour to clean it.
2) The man is so fool that no one took any notice of him.
=> He is such a foolish man that no one took any notice of him.
3) The film is so long that they can't broadcast it on one night.
=> It is such a long film that they can't broadcast it on one night.
4) The books are so interesting that we have read them many times.
=> They are such interesting books that we have read them many times.
5) The news was so bad that she burst into tears on hearing it.
=> It was bad enough for her to burst into tears on hearing it.
6) The food was so hot that it turned my tongue.
=> It was hot enough to turn my tongue.
7) There is so much rain that we can't go out.
=> There is such a lot of rain that we can't go out.
8) The boy is so fat that every calls him Stuffy.
=> He is fat enough to be called Stuffy.
9) The milk is so excellent that all the children want some more.
=> It is too excellent for children to want some more.
10) The weather was so warm that they had a walk in the garden.

=> It was warm enough for them to have a walk in the garden.
11) There were so many people in the hall that we couldn't see him.
=> There were such a lot of people in the hall that we couldn't see him.
12) The match was so exciting that all the fans shouted loudly.
=> It was such an exciting match that all the fans shouted loudly.
13) They drank so much coffee that they couldn't sleep all night.
=> They drunk such a lot of coffee that they couldn't sleep all night.
14) Alice had so many exercises to do that she couldn't go out.
=> Alice had such a lot of exercises to do that she couldn't go out.
15) The woman was so poor that she needed everyone's help.
=> She was too poor to be needed everyone's help.
DẠNG 3
VIẾT LẠI CÂU DÙNG CÂU ĐIỀU KIỆN : IF
TRong chương trình lớp 9 chúng ta chỉ cần học câu điều kiện loại 1 và 2 mà thôi,
công thức như sau:
LOẠI 1 :
Bên có IF dùng thì hiện tại đơn
Bên không có IF dùng tương lai đơn
LOẠI 2 :
Bên có IF dùng thì quá khứ đơn ( thay was = were)
Bên không có IF dùng tương lai trong quá khứ ( would + nguyên mẫu )
- Can/ could có thể thay thế will/ would
CÁCH CHUYỂN TỪ CÂU THƯỜNG SANG CÂU ĐIỀU KIỆN:
- Nếu câu đề là hiện tại - hiện tại / tương lai thì dùng loại 2 + phản nghĩa .
It is rainy. I can't go to school.
If ........
=> If it weren't rainy, I could go to school.
- Nếu câu đề là : tưong lai - tương lai thì dùng loại 1 (không phản nghĩa )
I will go to VT. I will buy you a present.
If ...

If I go to VT, I will buy you a present.
- Nếu câu đề là : Don’t V…….or + mệnh đề thì viết lại là :
If you V ( viết lại hết ,bỏ or )
Don’t go out or you will get wet.
=> if you go out, you will get wet.
- Nếu câu đề là: V …….or + mệnh đề thì viết lại là :
If you don’t V ( viết lại hết ,bỏ or )
Raise your hand or I will kill you.
=> If you don’t raise your hand, I will kill you.
Lưu ý :
Nếu trong câu có because , so(= that’s why) thì phải bỏ ( đặt if vào chổ because ,
còn so(= that’s why) thì ngựoc lại )
1) He can’t go out because he has to study for his exam.
=> If…….
2) She is lazy so she can’t pass the exam.
If…….
3) He will pay me tonight; I will have enough money to buy a car.
=> If…….
4) He smokes too much; that’s why he can’t get rid of his cough.
=> If…….
5) She is very shy, so she doesn’t enjoy the party.
=> If…….
6) I will get a work permit. I will stay for another month.
=> If…….
7) He doesn’t take any exercises. He is so unhealthy
=> If…….
8) We can’t get the ticket because I don’t have the right change.
=> If…….
9) Study hard or you won’t pass the exam.
=> If…….

10) Don’t be impatient or you will make mistakes.
If…….
key1) He can’t go out because he has to study for his exam.
=> If he had to study for his exam, he could go out.
2) She is lazy so she can’t pass the exam.
=>If she were lazy, she could pass the exam.
3) He will pay me tonight; I will have enough money to buy a car.
=> If he pays me tonight, I will have enough money to buy a car.
4) He smokes too much; that’s why he can’t get rid of his cough.
=> If he didn’t smoke too much, he could get rid of his cough.
5) She is very shy, so she doesn’t enjoy the party.
=> If she weren’t very shy, she would enjoy the party.
6) I will get a work permit. I will stay for another month.