CONDITIONAL

SENTENCES

Introduction

Conditional Sentence(if-clause ) หมายถึ�งประโยคเง��อนไข ซึ่��งประกอบด้�วยข�อความ 2 ส่�วน ค�อ if-clauseและ main-clause

เช่�น If he comes , I will tell him. (if- clause ) (main clause)

Conditional Sentence แบ่�งออกเป็น 4 ป็ระเภท คื�อ 1. Future Possible

2. Present Unreal 3. Past Unreal 4. Mixed Type

Future Possible

หมายถึ�งประโยคที่!�แส่ด้งความเป"นไปได้� เก#ด้ข�$นได้� ประกอบด้�วย

If + present simple ,future simple

(V1) (will +V1 ) หร�อ Future simple + if present simple (will + V1 ) (V1)

ตั�วอย่�าง If he studies hard,he will scceed.

She will stay at home if it rains

หมาย่เหตั�1. กร#ยาใน main clause อาจจะใช่� may, can,

must, (be ) going to แที่น will, shall ได้� are

going to ตั�วอย่�าง If you don’t hurry ,you may

miss the train can must

2. บางคร'$งกร#ยาใน if clause ใน main clause ใช่� present tense อาจจะใช่� when หร�อ whenever แที่น if ได้� เช่�น If ( when, whenever ) the weather is good.I play tennis

If (when ) the teacher asks ,answer her.

3. ถึ�า if clause ม! should อย(�ด้�วย ส่ามารถึที่)าให�เป"น infintive form ได้� โด้ยตั'ด้ if ออก และน)า should ข�$นมาไว�หน�าประธาน เช่�น

If she should telephone ,tell me at once.

Should she telephone ,tell me at once.

Present Unreal

หมายถึ�งประโยคที่!�แส่ด้งถึ�งการส่มมตั#ว�าเหตั,การณ์.น'$น เก#ด้ข�$นในป/จจ,บ'น แตั�ความจร#งไม�ได้�เก#ด้ข�$น เป"นเร��องที่!�ตัรงข�ามก'บความจร#ง ประกอบด้�วย

If + past simple (V2) , past future simple(could,might,would,should + V1)

Verb to be (V2) ใช่� were ที่,กบ,ร,ษ หร�อ Past future simple if + past simple

ตั�วอย่�างIf I were rich , I should travel around the world.

( but I am not rich)He would meet her if he went to the party.

(but he doesn’t go to the party.)

หมาย่เหตั�• ส่)าหร'บประโยคที่!�ม! were น'$น ที่)าให�เป"น Inverted Form ได้�ด้�วยการตั'ด้ if ออก ใช่� were ข�$นตั�นประโยค แล�วตั�อด้�วยประธานและส่�วนขยายอ��นๆ เช่�น

• If I were rich ,I should travel around the world.

= Were I rich, I should travel around the world.

Past Unreal

หมายถึ�งประโยคที่!�แส่ด้งถึ�งการส่มมตั#ว�าเหตั,การณ์.น'$นเก#ด้ข�$นในอด้!ตั แตั�ความจร#งไม�ได้�เก#ด้ข�$นเป"นเร��อง

ที่!�ตัรงข�ามก'บความจร#ง ประกอบด้�วย

If+ past perfect tense, past future perfect ( had+V3) (could,might would,should+have+V3)

หร�อ

Past future perfect if + past perfect tenseตั�วอย่�างIf she had been there, she would have seen the accident. (but she wasn’t there)He would have given her money if she hadn’t gone out. (but she went out)

ส่)าหร'บประโยคที่!�ม! had + V3 ที่)าให�เป"น Inverted Form ได้� ด้�วยการตั'ด้ if ออก ใช่� had ข�$นตั�นประโยคแล�วตั�อด้�วย

ประธาน + V3 + ส่�วนขยายอ��นๆ เช่�นIf she had been there , she would have seen the accident.(Had she been there , she would have seen the accident.)He would have given her money if she hadn’t gone out.(He would have given her money hadn’t she gone out.)

หมาย่เหตั�

Mixed Types

เป"นแบบผส่มระหว�าง Past Unreal และ Present Unrealประกอบด้�วย Past Unreal

Present UnrealIf + past perfect , past future simple ( had + v3 ) ( would + v1 )

past future simple if + past perfect ( would + v1 ) ( had + v3 )

หร�อ

ตั�วอย่�าง• If you had gone to bed early last night,

you would be in Chiengmai today.

เม��อค�นถึ�าค,ณ์เข�านอนแตั�ห'วค)�า ว'นน!$ค,ณ์ก3คงอย(�ที่!�เช่!ยงใหม� ความจร#ง ก3ค�อ เม��อค�นค,ณ์นอนด้�ก และว'นน!$ค,ณ์ก3ย'งอย(�ที่!�น!�

you would be in Chiengmai today if you had gone to bed early last night.

หมาย่เหตั�ส่)าหร'บประโยคที่!�ม! had + v3 ที่)าให�เป"น Inverted Form ได้�

ด้�วยการตั'ด้ if ออก ใช่� had ข�$นตั�นประโยคแล�วตั�อด้�วยประธาน + v3 + ส่�วนขยายอ��นๆ เช่�น

If you had gone to bed early last night, you would be in chiengmai today.(Had you gone to bed early last night, you would be in chiengmai today.)You would be in Chiengmai today if you had gone to bed early last night.(You would be in Chiengmai today , had you gone to bed early last night.)

การสั�บ่ตั�าแหน�งของ Subject และกร�ย่าช่�วย่ โดย่ละ if

ตั)าแหน�งใด้ที่!�ม! if ตัามด้�วยกร#ยาช่�วย เช่�น were,had หร�อ should ส่ามารถึที่!�จะส่'บ

กร#ยาช่�วยก'บประธานได้� โด้ยละ if เช่�นIf I were rich = Were I richIf he had known = Had he

known.If war should break out = Should

war break out.

If onlyonly ใช่�ตัามหล'ง if ได้� และช่!$ให�เห3นถึ�งความหว'ง (hope) ความปรารถึนา (a wish) หร�อเส่!ยใจ (regret)If only + present tense / will แส่ด้งความหว'งIf only he comes in time = we hope he will come.If only he will listen to her = we hope he will be willing to listen.If only + past / past perfect แส่ด้งความเส่!ยใจ(ม!ความหมายเหม�อนก'บ wish + past หร�อ past perfect)

we wish he didn’t drive so fast.If only he didn’t drive so fast

= We are sorry he drives so fast.

ตั�วอย่�างเพิ่�#มเตั�ม• แบบที่!� 1

- If you have really mislaid the document you had better inform the police.- The dog won’t attack you if you sit quite still.

• แบบที่!� 2- Why did he ask if he knew already?- If I were you I should say nothing about it.

• แบบที่!� 3- But for my lifebelt I should have been drowned.- We might have had lobster for lunch if the cat hadn’t stolen it.

คื�าท$#แสัดงเง�#อนไขif = ถึ�า ส่มม,ตั#ว�าunless = นอกจากว�า ถึ�าหากว�าไม�on condition that = ถึ�าหากว�า โด้ยม!เง��อนไข

ว�าas(or so) long as = ถึ�าหากว�า ตัราบใด้ก3provided (that) = ถึ�าหากว�าproviding (that) = ถึ�าหากว�าsuppose (that) = ถึ�าส่มม,ตั#ว�าsupposing (that) = ถึ�าส่มม,ตั#ว�าin the event that = ถึ�าหากว�า เผ��อว�าin case that = เผ��อว�า

If (ถึ�า ส่มม,ตั#ว�า ) ใช่�ในประโยคเง��อนไข (Condition) วางไว�หน�าประโยคหร�อกลางประโยคก3ได้�ตั'วอย�าง If he works hard , he will pass the examination. He will pass the examination if he works hard. If she went to the party , she would meet her friends. She would meet her friends if she went to the party. If I had sent this letter , they would have received it. They would have received this letter if I had sent it.

unless = if…not (นอกจากว�ามถึ�าหากว�าไม�) วางไว�หน�าประโยคหร�อกลางประโยคก3ได้�

ตั'วอย�าง He won’t let you go out unless you finish that work

He won’t let you go out if you don’t finish that work

She won’t go to the seaside unless the weather is fine

She won’t go to the seaside if the weather is not fine

on condition that , as (or so) long as , provided(that) , providing(that) , (ถึ�าหากว�า, โด้ยม!เง��อนไขว�า, ตัราบใด้ที่!�) วางไว�กลางประโยค

ตั'วอย�าง on coundition that I will help you as long as you obey me

He will go to Phuket provided(that) he can afford the time providing(that)

suppose(that ) , supposing(that) = (ถ้'า, สัมม�ตั�ว�า ) ม$คืวามหมาย่เช่�นเด$ย่วก�บ่ if วางไว'หน'าป็ระโย่คื

ตั�วอย่�าง 1. Suppose (that) he is rich , he will go abroad.

2. Supposing (that) she saved money all year , she would have enough money for her vacation.

in the event (that) , in case (that) = (ถึ�าหากว�า , เผ��อว�า) วางไว�หน�าประโยคหร�อกลางประโยคก3ได้�

ตั'วอย�าง 1. In the event (that) the weather is fine , they will play badminton.

2. In case (that) a few members come , the conference will be postponed.

Exercise1. If I can find a cheap room__________a fortnight.a. I stayb. I would stayc. I will stayd. I stayed

2. If the pain __________you’ d better take another pill.a. return b. returnsc. returnedd. Would have retured

3. If you had shut the door, the hens__________into the house.a. will not getb. Would not getc. would not have gotd. Would have not got

4. The Customs officer will not keep you long_______ you are dishonesta. if b. Unlessc. ford. Or

5. My friend acts as if he _________ English perfectly.a. knowb. Knowsc. knewd. Had known

6. If I __________a bird, I would be very happy.a. would be b. Werec. can dod. Would have been

7. Do you mind_______________?a. If I smokeb. That I smokec. If I am smokingd. Whether I smoke

8. If anybody____________ question, please ask me after class.a. hasb. Havec. have thed. has a

9. If you are tired, go and__________ for a while.a. to restb. Restc. restingd. Rested

10. ____________ and we’ll finish the work.a. Please give us toolsb. Give us toolsc. You can give us toolsd. If you gave tools to us

เฉลย่ 1.c

2.b3.c4.b5.c6.b7.a8.d9.b10.b

11. Had the government transferred television stations to the Mass Media Organization of Thailand , the workers protested.

a.Would have

b.Could have

c.Should have

d.had

12. We in such a great mess now if we

it before.

a.wouldn’t have been ………..have know

b.wouldn’t be ………… had know

c.won’t have been ………….have know

d.Won’t be ……….knew

13. “ I’m sorry that I am late , It took more time to

get here than I expected. ”

“ You sooner , if you the early

bus before the rush hour. ”

a.can arrive – had taken

b.could arrive – would have taken

c.Would have arrive – had taken

d.had arrive – would have taken

14. you in my position , what would you do ?

a.Unless

b.Had

c.If

d.Were

15. If it fine yesterday , we’d have reached our destination by now.

a. were

b. was

c. had been

d. has been

16. If I had not come here last week , I

out all the truth about him.

a.should not find

b.found

c.did not find

d.should not have found

17. Had we had a helicopter , we their lives.

a.might save

b.may saved

c.might have saved

d.might be saved

18. If he the man guilty , he would send

him to prison.

a.has found

b.found

c.find

d.was finding

19. If he here yesterday , I’d have given

him this letter.

a.were

b.have come

c.had come

d.would come

20. If you ill , send for me at once.

a.are

b.were

c.was

d.had been

21. on time , they would have seen the entire show.

a.Should they arrive

b.Had they arrived

c.Have they arrived

d.If had they arrived

22. If I were still a poor student , I would not go on holiday as often as I .

a.was

b.do

c.go

d.would

23. Do you mind if I the window?

a.opening

b.will open

c.opened

d.open

24. If I you , I wouldn’t return to call.

a.was

b.be

c.am

d.were

25. If it rain tomorrow , we’ll have a picnic.

a.didn’t

b.wouldn’t

c.doesn’t

d.won’t

26. We would have been in time if we five minutes earlier.

a.had stared

b.started

c.have started

d.were stared

27. If you to know what everyone thinks about the government , the man in the street.

a.will ask

b.ask

c.have asked

d.asking

28. If everybody the traffic rules , the road will be .

a.Obeys………more safe

b.Obeys………more safer

c.Obey……….much more safer

d.Obeys………much safer

29. Don’t eat that apple , it is ripe.

a.since

b.unless

c.as if

d.in case

30. We had heard nothing of what happened she told us.

a.because

b.until

c.otherwise

d.but that

31. She will go to Rayong , her expenses are paid .

a.inasmuch as

b.provided that

c.or else

d.for

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