CONDITIONAL SENTENCES (Câu điều kiện)

1. Các cách dùng cơ bản (Usage)
a. Loại 1: Diễn tả điều có thật ở hiện tại:
- Câu điều kiện loại 1 còn có thể được gọi là câu điều kiện hiện tại
có thể có thật. Ta sử dụng câu điều kiện loại 1 để đặt ra một điều
kiện có thể thực hiện được trong hiện tại hoặc tương lai
FORM: If + S + V/V(s,es,ies) (present simple), S + will + V (inf)
Note:
V + ............ + or + S + will/won't / can/ shall+ V + .....
=> Unless S + V + ............ , S + will/ won't + V + ............
=> If S don't/ doesn't + V, S + will/ won't + V + ............
EX: Study hard or you will fail the exam.
=> Unless you study hard, you will fail the exam.
=> If you don't study hard, you will fail the exam.
Ghi chú: - Sau mệnh đề If hoặc mệnh đề Unless phải có dấu phẩy (,)
- Sau Unless không được dùng dạng phủ định
Trong câu điều kiện loại 0, I và II, chúng ta có thể sử dụng một số
từ, cụm từ như so/as long as, when, provided/providing that, in
case, unless… để thay thế cho if.

1. Put the verbs in brackets into the correct form.
recycle more, we (help) ……………the
will help
1. If we (recycle) …………
Earth.

won't dump

fines …………………waste into rivers if the
2. Factories (not dump)
travel them heavily.
will be
government (fine) ………
3. If people (travel) …….. to work by bus, there (be) …….........
will save
fewer car fumes.
do(save)
not waste
4. We
……………thousands of trees if we (not waste)
use
…………………........
paper.
will
have
5.
If we
(use) …............water carefully, more people (have)
……........... fresh water.

2. Combine each pair of sentences to make a conditional
sentence type 1.

1. Students are more aware of protecting the environment. Teachers
teach environmental issues at school.
Students will be more aware of protecting the environment if teachers
teach environmental issues at school.
2. Light pollution happens. Animals change their behaviour patterns.
When light pollution happens, animals will change their behaviour
patterns.
3. The levels of radioactive pollution decrease. We switch from nuclear
power to renewable energy sources
The levels of radioactive pollution will decrease if we switch from
nuclear power to renewable energy sources.
4. The water temperature increases. Some aquatic creatures are unable
to reproduce.
If the water temperature increases, some aquatic creatures will be
unable to reproduce.
5. People get more diseases. The water is contaminated.
People will get more diseases if the water is contaminated.

b. Loại 2: Điều kiện không có thật ở hiện tại:
- Câu điều kiện loại 2 diễn tả sự việc, hiện tượng không thể xảy ra ở
hiện tại hoặc tương lai.
FORM: If + S + V2/ Ved, S + would /could/should + V1
EX: If I had money, I would buy the car.
*Note: Động từ “to be” phải chia là were ở tất cả các ngôi
EX: If I were rich, I would travel around the world.
c. Loại 3: Câu điều kiện loại 3 là câu điều kiện không có thực trong
quá khứ.
Điều kiện không thể xảy ra trong quá khứ, chỉ mang tính ước
muốn trong quá khứ, một giả thiết trái ngược với thực trạng ở
quá khứ.

FORM: If + S + had + V3 / Ved , S + would /could+ have + V3/Ved
EX: If I hadn't been absent yesterday, I would have met him.

3. Match an if-clause in A with a suitable main clause in B.

A
1. If I were you,
2. If Lan wasn't ill,
3. If there were fewer
cars on the road,

B

Answer

a. what would happen?

1 +b

b. I'd look for a new
place to live.

2 +c

c. she would join our tree
+d
3
planting activity.

4. If people really cared
about the environment,

d. there would be less
pollution.

5. If there was no fresh
water in the world,

e. they wouldn't dump
waste into the lake.

4 +e
5

+a

4. Put the verbs in brackets into the correct form.
would you do
were
1. If you (be) ………….
the president, what you (do) ……………
to help the environment?
exercised more,
2. They get sick so often. If they (exercise) …………….
would be healthier.
they (be) ……………
had one million US dollars, I (build) would
build
3. If I (have) ………
…………
more parks in our city.
tidied her room
4. Ngoc's mother is unhappy. If Ngoc (tidy) ………..
wouldn't be so upset.
every day, her mother (not be) …………………
was/were ,
5. There isn't a garden at our house. If there (be) …………….
would grow vegetables.
we (grow) …………………

5. Write a conditional sentence type 2 for each situation, as in the example.

2. There are so many billboards in our city. People cannot enjoy
the view.
→ If there weren't so many billboards in our city, people
could enjoy the view
3. There is so much light in the city at night. We cannot see the
stars clearly.
→ If there wasn't/ weren't so much light in the city at
night, we could see the stars clearly
4. We turn on the heater all the time. We have to pay three million
dong for electricity a month.
→ If we didn't turn on the heater all the time, we wouldn't have
to pay three million dong for electricity a month.
5. The karaoke bar makes so much noise almost every night. The
residents complain to its owner.
→ If the karaoke bar didn't make so much noise almost every
night, the residents wouldn't complain to its owner.
6. She has a headache after work every day. She works in a noisy
office.
→ She wouldn't have a headache after work every day if she
didn't work in a noisy office.

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