Thể khẳng định Khẳng định (Đổi mệnh đề chính sang thể ngược lại) If I have time, I will help you.. .[r]
(1)IF clause / If not/ unless
- câu điêù kiện loại 1(có thật tại)
If +S + V(simple present ), S + will (can, may) +V -câu điều kiện loại 2(không co thật tại)
If +S+V (simple past),S + could, would + V 3.-câu điều kiện loại 3(khơng có thực q khứ)
If +S+V(past perfect), S+would, could + have + PII
4 IF = UNLESS
UNLESS = IF NOT: … ko/ trừ phi
Cách chuyển mệnh đề IF sang mệnh đề UNLESS If – Clause Unless
Thể phủ định Khẳng định ( Mệnh đề ko đổi) - If you don’t study hard, you will fail the exam
Unless you study hard, you’ll fail in the exam - If she doesn’t water the trees, They will die
Unless she waters the trees, they will die
Thể khẳng định Khẳng định (Đổi mệnh đề sang thể ngược lại) If I have time, I will help you
Unless I have time, I won’t help you
If we had more rain, our crops wouldn’t grow faster
(2)1) Câu điều kiện loại I
chỉ điều kiện có thật sảy tương lai (phù hợp với thực tế) If +S + V(simple prerent) , S + will (can, may) +V
Ex :If It's sunny , we will go camping (nếu trời nắng, cắm trại)
nếu câu phủ định :
If + S + don't / doesn't + V , S + willn't (can't , ) + V Ex : If he doesn't morning exercise , he will feel tired.
(nếu không chịu tập thể dục cảm thấy mệt mỏi) 2) Câu điều kiện lọai II
Chỉ hành động sảy tương lai (điều kiện đặt trái với thực tế) If + S + V (simple past) , S+ could(should, would) + V
Ex : If It rained , we should stay at home.
(Nếu trời mưa, nhà ) trời khơng mưa câu phủ định thì:
If+S + didn't + V , S + wouldn't (shouldn't, couldn't) + V
Ex : If It didn't rain , we shouldn't stay at home
( trời không mưa , không nhà) trời mưa
Lưu ý: động từ tobe với chủ ngữ " were "
3) Câu điều kiện loại III
Diễn tả hành động trái với thực tế sảy khứ
If + S + had +PII ,S+ would (should,could) + have + PII
Ex : If Lan had learned, she should have got a good mark.
(3)Câu phủ định :
If + S+ hadn't + PII, S+ wouldn't (couldn't, shouldn't)+have + PII
Ex : If I hadn't been tired , I wouldn't have missed the TV (nếu không bị mệt không bị lỡ chương trình TV ) bị lỡ
EXERCISES
Supply the correct form of the verbs Cats could fly if they (have) wings
2 If Peter (study) harder, he would get better marks You will be late for class if you (not, hurry)
4 Mary would not have got wet if she (wear) a raincoat If today (be) a holiday, I would stay in bed for all day long
6 If she (make) him change his mind, she would save him a lot of trouble I wish he (come) tomorrow
8 I wish it (be) a little warmer I feel very cold
9 I saved some money at the bank, but it was not enough to buy a car I wish I (have) enough money to buy a car
10 I wish out teacher (explain) that lesson to us again tomorrow
11 I can hear his voice so clearly that it is as if he (be) hear but the fact is that he isn't here 12 I have never met her before in my life Why is she looking at me as if she (know) me? 13 If I (be) a bird, I (not, want) to live in a snake
14 My brother managed to kill the snake just at the time when I (be) almost exhausted If he (be) a little late, I (kill) by the snake
15 Had I know you were ill, I (visit) you 16 Were he here, he (not, do) it
(4)18 He talks as though he (know) where she was 19 He looked frightened as if he (see) a ghost
20 If you (smoke) less, you (have) much more money But I don't think you ever will
II Supply the correct verbs
1) If I (know) that you were ill, I (go) to see you 2) If she'd had enough, She (buy) a car
3) I (buy) a car If you lend me some money 4) I (see) him if I (go) to the party last night
5) We could have gone out if the weather (not be) so bad 6) If the book (not be ) expensive, I'll buy it
7) You would be very surprised if he (return) 8) I'll go out if it (not rain)
9) They wouldn't come to the party if you (not invite) them 10) What you (do) if you (be) him?
IV Put the verbs in the brackets into the correct tenses: If I see him, I (give) him a gift
2 If I had a typewriter, I (type) it myself
3 If I had known that you were in hospital, I (visit) you
4 You could make better progress if you (attend) class regularly If I (know) his telephone number, I’d give it to you
6 If you (arrive) ten minutes earlier, you would have got a seat He could get a job easily if he (have) a degree
(5)10 He might get fat if he (stop) smoking
11 What you (do) if you found a burglar (kẻ chộm) in your house? 12 If she (not hurry), she may be late
13 If I (try) again, I think that I would have succeeded
14 If I tell you a secret, you (promise) not to tell it to any one else? 15 Tell him to ring me if you (see) him