1. Grammar I. Permission II. Possibility III. Necessity IV. Obligation

2. I. Permission I was trapped in the glass I am completely free. I’ll do what I wanted. → I can do what I wanted.

3. Today, snow is falling hard. →Mommy won’t let me go to my friend’s house to learn in group. →I can’t go to my friend’s house.

4. Standing on the grass is banned. → You mustn’t stand on the grass.

5. A. Present and future Can, can’t, mustn’t are used to describe what is allowed or not allowed

6. In EuropeIn China In Europe, man and woman talk to each other naturally. In China, they do not. → In the old day, Chinese female couldn’t express intimacy to male.

7. When I was eight, my parents let me sent Christmas cards to relatives by myself. → When I was eight, I was allowed to send Christmas cards to relatives by myself

8. B. Past Could : to report that in the past s.o had general permission to do sth, that is, to do it at any time eg. Last century, women couldn’t vote. Was/ were allowed to : report permission for one particular past action. eg. Although he didn’t have a ticket, Ken was allowed to coming.

9. Notes Give permission not to do something needn’t/ don’t need to eg.You needn’t cut the grass, I’ll do it later. You don’t need to cut the grass, I’ll do it later

10. Ask permission to do something can/ could/ may/ might Can/ could I take another biscuit? particularly polite

11. Might I invite you to dance? No, thank you. I’m waiting for another more handsome man.

12. Give/ refuse permission to do something can/ can’t/ may/ may notformal Ok. You can stay in the room no, you may not have another chocolate. I’m sorry, no, you can’t borrow the car tonight.

13. II. Possibility The phone is ringing. → It is Tim or it is not Tim → It could be Tim.

14. Sometimes mountain daisies are yellow, sometimes they are pink. → Mountain daises can be yellow or pink.

15. It may rain now. It may rain later.

16. A. Present To describe the possibility of something happening or being true: may/ might/ can/ could less possibility →we are giving an opinion about which we are unsure.

17. Jack had a car crash yesterday but he’s alright. →He’s lucky- he could have hurt himself badly.

18. B. Past To describe things were possible but did not happen could/ might have (done) Eg. The situation was bad but it could have been worse. The plan might/ could easily have gone wrong, but in fact it was a great success.

19. Notes Don’t use ‘may’ to ask questions about the possibility of something happening Could it be that you don’t want to leave? Are you likely to be visiting Greece again this summer? Might they be persuaded to change their mind? rather formal

20. may/ might/ could + well/ conceivably/ possible →To say it is likely that something will happen The profits of the company may well reach $100 million this year. I can well recall how I felt when John told us he was moving to South Africa. →can well is used to talk about something we think or feel now.

21. May/ might/ could + well/ conceivably/ possibly + have + p.p →to say it’s likely that sth would have happened in the past if circumstances had been different →by some time in the future it’s likely that something will have happened I may conceivably have been tempted to take the job if it had been nearer home. By this time next week, I might well have left for Washington.

22. There are plans to rebuild the town centre,… …, but it can’t/ couldn’t happen for another 10 years. (it isn’t possible that it will happen for another 10 years) →can’t/ couldn’t: to say that it is not possible that sth is true. …, but it may not/ might not happen for another 10 years. (it is possible that it won’t happen for another 10 years) →may not/ might not: to say that it is possible that sth is not true.

23. She was too far away, so she couldn’t have seen you. (it is not possible that she saw you) A: I wonder why she didn’t say hello B: She might not have seen you. (perhaps she didn’t see you; perhaps she did)

24. III. Necessity Your niece has broken my windows. I have to go right now hehehe.

25. I am too hungry. I must eat now.

26. To say that it is necessary to do sth must/ have got to/ will have to/ have to must: personal feeling eg. She’s a really nice person. You must meet her (I say this necessary) Have to: impersonal, used for fact eg. You can’t turn right here. You have to turn lelf. (because of the traffic system) Have got to: talk about the necessity that is characteristic of a person eg. Ann has got to have at least eight hours’ sleep at night.

27. You don’t use microphone, anyone still hear you clearly. →You don’t need to use microphone. Anyone can hear you clearly Although you speak loudly, no one hear us. →You needn’t whisper. Nobody can hear us.

28. A. Present Not necessary: needn’t/ don’t need to/ don’t have to/ mustn’t Eg. They proved that watching a chess match needn’t be boring We needn’t go into details now, but we seem to agree on the general principles.

29. I cooked a dinner. Nick couldn’t go home because of meeting. →If I had known the news, I wouldn’t have cooked. →I needn’t have cooked dinner.

30. Why did you wash that shirt? It wasn’t dirty at all. → That shirt wasn’t need to be washed → You needn’t have washed it.

31. “need not have + pp” → to show that we think something that was done was not. → “I did something but now I know that it was not necessary.”

32. Nick phoned to say that he couldn’t come to eat because of meeting → Therefore, I didn’t cook the dinner. → I didn’t need to cook dinner. = I didn’t have to cook dinner.

33. Didn’t need to/ didn’t have to → it was not necessary to do something in the past, and it wasn’t done

34. Notes May/ might as well do sth = should do sth because there is nothing better to do and there is no reason not to do it eg. What time are you going? Well, I’m ready, so I might as well go now. The buses are so expensive these days, you might as well get a taxi.

35. You should have done something = you didn’t do it but it would have been the right thing to do eg. I wonder why they’re so late. They should have been here an hour ago. She shouldn’t have been listening to our conversation. It was private.

36. IV. Obligation This soup is too salty! Send it back right now! → You should/ ought to send it back!

37. You’ll catch cold if you go out like that. Take a hat with you → You should / ought to take a hat.

38. We should/ ought to create cozy atmosphere in family. Brothers should/ ought to love each others.

39. A. Present Should/ ought to Obligation in giving advice or making recommendation Obligation in talking about a responsibility or duty

40. B. Past Should/ ought to + have + p.p →obligation in the past, often indicate some criticism or regret.

41. Notes (be) supposed to: commonly used in spoken E to express less strong obligation eg. I’m supposed to be there at 10:0 The work was supposed to start last week.

42. Had better To say that it would be sensible or advisable to do sth in particular situation Do not used to talk about the past or to make general comments eg. If you’re not well, you had better ask Ann to go instead There is always a danger or a problem if you don’t follow the advice eg. The film starts at 8:30. You’d better go now or you’ll be late