CONDITIONAL SENTENCES

CONDITIONAL SENTENCE – IF CLAUSE
CÂU ĐIỀU KIỆN – MỆNH ĐỀ IF

I. Cơng thức
TYPE
Loại 1

Loại 2

Loại 3

USE
Sự việc có thể
xảy ra ở
hiện tại
hoặc
tương lai

IF CLAUSE
( Mệnh đề If )

S + am / is / are
S + V1/s/es
S + don’t / doesn’t + V1

MAIN CLAUSE
( Mệnh đề chính )

S + will / can / may + (not) + V1
(?) Will / Can / May + S + V1…?
NOTE: Đối với MĐ chính của If Loại 1

- Để chỉ 1 qui luật tự nhiên
 dùng: S + V1/s/es
- Để ra lệnh  dùng: V1 …. / Don’t + V1….

Sự việc khơng có S + V2/ed / (be were)
thật ở hiện tại
S + didn’t + V1

S + would / could / might + (not) + V1
(?)Would / Could / Might + S + V1…?

Sự việc khơng có S + had + V3/ed
thật ở q khứ
S + hadn’t + V3/ed

would
S + could + (not) + have + V3/ed
might
Would
(?) Could + S + have + V3/ed …?
Might

Ex 1: He (do) …………………….the gardening if the weather (be)…………… fine tomorrow.
Ex 2: I (drive) …………………. everywhere if I had a car.
Ex 3: If you (meet) ………..………the president yesterday, what …….... you (do)…………….….?
Ex 4: Come to see me if you (have) ……………….. time.
PRACTICE : Supply the correct form of the verbs.
1. If I had enough money, I………..…abroad to improve my English.
a. will go
b. would go

c. should go
d. should have gone
2. We’ll get wet if we ………….out.
a. go
b. did go
c. went
d. had gone
3. If I go shopping, I ………some food.
a. buy
b. will buy
c. would buy
d. would have bought
4. If I find it, I ………you.
a. will tell
b. would tell
c. had told
d. told
5. What would you do if you……………a million dollars?
a. would win
b. win
c. had won
d. won
6. They‘d be hurt if I …………..
a. don’t go
b. didn’t go
c. hadn’t gone
d. wouldn’t go
7. If we took the 6: 30 train, we………… too early.
a. would have arrived b. arrived
c. will arrived

d. would arrive
8. If I had known you were in hospital, I …………to see you.
a. will go
b. would go
c. went
d. would have gone
9. If I …………., I would have said hello.
a. had seen
b. see
c. saw
d. would see
10. I…………..out if I hadn’t been so tired.
a. will go
b. went
c. would
d. would have gone
11. If it……… tomorrow, we may postpone going.
a. rains
b. will rain
c. shall rain
d. raining
12. If it……………, they will go out tonight.
a. rains
b. rained
c. doesn’t rain
d. is raining
13. If Jake…….... to go on the trip, would you have gone?
a. doesn’t agree
b. didn’t agree
c. hadn’t agreed

d. wouldn’t agree
14. If I weren’t working for an accounting firm, I ……… in a bank.
a. work
b. will work
c. have worked
d. would be working
15. If she ……....him, she would be very happy.
a. meets
b. will meet
c. is meeting
d. met
16. If he ……... knowledge of English, he could have applied for this post.


a. had had

b. had

c. has

d. has had

II. Ghi chú
1. Đề cho dấu hiệu thời gian ở Tương lai/ Câu mệnh lệnh  Dùng If loại 1
Hiện tại
 Dùng If loại 2
Quá khứ
 Dùng If loại 3
Ex 5: Why didn’t you tell me ? If you (tell)….…………….… me, I (help)…….………………… you.
Ex 6: If there (not be) ……………………. water now, we (die) …………………..…….

Ex 7: If she (not drive) ………………………so fast, her car (not crash)……………………………….. into a
tree last night.
2. UNLESS = If … not (nếu … khơng)
Sau Unless khơng dùng hình thức phủ định
=>If (có not) = Unless (bỏ not), Mệnh đề chính giữ nguyên
If (không not) = Unless (giữ nguyên), nhưng trái nghĩa mệnh đề chính
Ex 8: If you don’t study hard, you’ll fail in the exam.
 Unless ………………………………………………………………
Ex 9: If she doesn’t water these trees, they will die.
 Unless ………………………………………………………………
Ex 10: If she calls me, I will wait for her.
 Unless ………………………………………………………………
Ex 11: If we had more rain, our crops would grow faster.
 Unless ………………………………………………………………
Ex 12: Stop smoking or you will die.  If ……………………………………………….
 Unless ………………………………………………………………
3.
Without
N
+
: Nếu khơng có …
Ving
= But for
Ex 13: If there weren’t any water, we couldn’t exist.
 Without / But for ……………………………………………………………………

4. INVERSION
a.) TYPE 1: IF + S + + V1 … , S+ WIIL / SHALL / CAN + V
 SHOULD + S + V1 … , S+ WIIL / SHALL / CAN + V
Ex 14: If you need more information, please contact me.

 Should ………………………………………………………………………
b) TYPE 2: IF + S + WERE … , S+ WOULD / COULD + V
 WERE + S …
, S+ WOULD / COULD + V
Ex 15: If I were you, I would help him. …………………………………………
Ex 16: If they came here late, they couldn’t see me
. Were………………………….……………………………………

c) TYPE 3: IF + S + HAD + V 3/ed … , S+WOULD/ COULD/ MIGHT + HAVE + V3/.ED
 HAD + S + V 3/ed …

, S+WOULD/ COULD/ MIGHT + HAVE + V3/.ED

Ex 17: We could have bought the house if we had had money.
…………………………….…………………………………………….
Ex 18: If he had studied hard , he would have passed his exam.
…………………………….…………………………………………….

5. Loại hỗn hợp giữa If Loại 2 và If Loại 3
IF CLAUSE :

TYPE 3

MAIN CLAUSE :

TYPE 2 S + WOULD / COULD / MIGHT + V1

IF + S + HAD + V 3/ed ,

: IF + S + HAD + V 3/ed

S + WOULD / COULD / MIGHT + V1

Ex 19: If I (go) ……………..…. to bed early last night, I (not be) …………………..tired now.

6. Những lưu ý khi dùng Mệnh đề If viết lại câu:


Vì MĐ If trái với sự thật nên khi viết lại câu: Mệnh đề nào có “not”  viết lại bỏ “not”,
Mệnh đề nào khơng có “not”  viết lại thêm “not”
Ex 20: They don’t tell us so we can’t know. If ………………………………………………………
Ex 21: We got lost because we didn’t have a map.
 If ………………………………………………………………………