Solution: Modals

• Is it likely that he have forgotten all about it?
• He is likely to have misunderstood you.
• She can't have sold her house.
• You aren't allowed to park here.
• He ought to have warned us about it.
• They are supposed to pay more attention.

Elementary: Modals

Modal verbs คือ can, could, may, might, must, ought to, will, would, shall, should

modal verb เหล่านี้จะไม่ผันในกรณีตามหลังประธานที่เป็นบุรุษที่สามเอกพจน์ (he, she, it) พูดง่าย ๆ ก็คือไม่เติม s นั่นเอง

รูปปฏิเสธทำได้โดยเติม not หลัง modal verb ทันที

ความหมายของ modal verbs มีหลายอย่าง เช่น

• ability: He can speak Chinese.
  
  
• possibility: She may be at home. (It is possible that she is at home.)
  
  
• probability: She ought to be home by now. (She will probably be home.)
  
  
• logical assumptions: He can't be serious. (I'm sure he's not serious.)
  
  
• permission: You may be excused. (formal)
  
  
• necessity: She has to sell the house.
  
  
• advice: You ought to abide by the rules.
  
  
• criticism: They should have told us.
  
  
• obligation: We ought to donate money to charity. (It's what we should do, but we don't always do it.)
  
  
• requests: May I borrow your pen?
  
  
• offers: Can I help you?
  
  
• suggestions: Shall we go now?
  
  
• prohibition: You may not talk during the test.
  
  
• duty: People ought to live in peace.

ทั้งนี้ก็มีคำที่มีความหมายคล้ายกับ modal verbs ได้ เช่น

• to be supposed to + inf.
  = should แต่จะเน้นว่ามีคนที่คาดหวังว่าจะเกิดเหตุการณ์อย่างหนึ่งขึ้น
  
  
• You're supposed to wear a suit.
  เจ้านายคาดหวังว่าคุณจะใส่สูทไปทำงาน
  
  
• You should wear a suit.
  คุณควรจะใส่เพราะมันทำให้คุณดูดี
  
  
• be to + infinitive
  = must
  
  
• be likely to
  = may
  
  
• would you mind
  ใช้กับ formal requests
  
  
• let's/how about/why don't we/what about?
  ใช้เชิญชวน เสนอแนะ
  
  
• be allowed to
  บอกการอนุญาต

ลองเปลี่ยนประโยคด้านล่างนี้ดูโดยใช้ modal verbs หรือ expressions อื่น

• Might he have forgotten all about it?
• He might have misunderstood you.
• I don't think she's sold her house.
• You can't park here.
• He should have warned us about it.
• They ought to pay more attention.
  

Solution: Had better

แบบฝึกหัดนี้คงจะไม่ยากเกินไปใช่ไหม :)

• You should have locked the door before you set out.
  It would have been better if you had locked the door before you set out.
  
  
• You should go to bed as we have to be up early tomorrow.
  You had better go to bed as we have to be up early tomorrow.
  
  
• You should have asked her opinion before making a decision.
  It would have been better if you had asked her opinion before making a decision.
  

Elementary: had better

had better แปลว่า should แบ่งได้เป็น 2 รูปคือ

• had better + Present infinitive
  ใช้กับเหตุการณ์ปัจจุบันหรืออนาคต แปลว่า ควรจะ
  
  He had better call his mother.
  เขาควรจะโทรหาแม่ของเขา (= He should call his mother.)
  

• It would have been better if + Past Perfect
  จะหมายถึงเหตุการณ์ในอดีต (ควรจะทำ แต่ไม่ได้ทำ)
  = should have V3 นั่นเอง (ถ้าจำรูปแบบนี้ไม่ได้ ดูที่ Auxiliaries + Perfect infinitives)
  
  It would have been better if you hadn't drunk too much last night.
  คงจะดีกว่านี้ถ้าคุณไม่ได้ดื่มมากเมื่อคืน (แต่จริง ๆ เมื่อคืนคุณดื่มมาก)
  

ลองเปลี่ยนประโยคต่อไปนี้โดยใช้ had better/it would have been better if ดู

• You should have locked the door before you set out.
• You should go to bed as we have to be up early tomorrow.
• You should have asked her opinion before making a decision.
  

Solution : Unless, Provided/Providing/On condition that

• If you don't work hard today, you can't have a holiday tomorrow.
  Unless you work hard today, you can't have a holiday tomorrow.
  

• I'll lend you the book if you return it next Monday.
  I'll lend you the book provided (that) you return it next Monday.
  

• I won't lend Peter money if he doesn't need it.
  I won't lend Peter money unless he needs it.
  

• If I don't have a quiet room, I won't able to do any work.
  Unless I have a quiet room, I won't be able to do any work.
  

• Go on to the next unit if you have already finished Unit 2.
  Go on to the next unit providing (that) you have already finished Unit 2.
  

• You can camp in my field if you promise to leave no mess.
  You can camp in my field on condition that you promise to leave no mess.

• Unless you wear boots, you may get bitten by snakes.
• If he goes into that field, the bull will chase him.
• You can't make tea unless you have hot water.
• He will divorce his wife unless she confesses her sins.
• Someone will steal your car if you leave it unlocked.

Elementary: Unless, Provided/Providing/On condition that

วันนี้มาพูดถึงเรื่องง่าย ๆ บ้างเกี่ยวกับ unless, provided (that), providing (that), on condition (that)

Unless มีความหมายว่า If .... not จะใช้ใน if clause ที่เป็นปฏิเสธดังนี้
If + negative clause .....................
= Unless + affirmative clause ........................

ตัวอย่างเช่น
I won't have lunch with him if he doesn't invite me.
= I won't have lunch with him unless he invites me.

อย่าลืมว่าพอประโยคกลายเป็นประโยคบอกเล่าแล้ว กริยาต้องผันตามประมาณ (เช่นเติม s แบบในตัวอย่าง)

ส่วน provided (that), providing (that), on condition (that) ใช้แทน if ในประโยค if clause ที่เป็นบอกเล่า (affirmative)

เช่น If you obey the rules, you will not be punished.

.........Provided|
........Providing| (that) you obey the rules, you will not be punished.
..On condition |

ทั้งสามคำนี้สามารถใช้แทนกันได้ ส่วน that จะใส่หรือไม่ใส่ก็ได้

ดูแบบฝึกหัดเลยละกัน เปลี่ยนประโยคด้านล่างโดยใช้ provided/providing/on condition that หรือ unless (แบบฝึกหัดและคำอธิบายวันนี้มาจาก Workbook 5 (M. 5) สาธิตจุฬาฯ)

• If you don't work hard today, you can't have a holiday tomorrow.

• I'll lend you the book if you return it next Monday.
  

• I won't lend Peter money if he doesn't need it.

• If I don't have a quiet room, I won't able to do any work.

• Go on to the next unit if you have already finished Unit 2.

• You can camp in my field if you promise to leave no mess.
  

อีกแบบฝึกหัด ให้เติม if หรือ unless ในช่องว่าง

• ______ you wear boots, you may get bitten by snakes.
• ______ he goes into that field, the bull will chase him.
• You can't make tea ______ you have hot water.
• He will divorce his wife ______ she confesses her sins.
• Someone will steal your car ______ you leave it unlocked.
  

GRE #1

ศัพท์ GRE (เอาเฉพาะความหมายที่ GRE เอามาออกสอบบ่อย ๆ)

• sanguine (adj.) ฟังเสียง
  hopeful, confident, optimistic, cheerful
  
  ตัวอย่าง
  He was so sanguine about the success of this trip.