Function and grammar

Function Talk about obligation or lack of obligation.

Activity1 Read the pairs of sentences and answer the questions. a You must arrive on time at a party. You have to arrive on time at a party. Question: Which of the following is true about the first pair of sentences? a)They both indicate an obligation. b)They are only suggestions about what to do. c)The first one is an obligation, the second one is a suggestion.

b. You mustn’t take yellow flowers for the host. You don’t have to take yellow flowers for the host. 2. Which of the following is true about the second pair of sentences? a) They mean the same thing. b) The first one is an obligation, the second one indicates a lack of obligation. c) The first one indicates that something is against the law.

C. You don’t have to take a lift. You don’t need to take a gift. Which of the following is true about the third pair of sentences? a) They mean the same thing. b) The first one is an obligation, the second one isn’t. c) The second one is an obligation, the first one isn’t.

Talk about obligation or lack of obligation. obligation: must do… have to do… 必须做 … 不得不做 … don’t have to do… don’t need to do… 没有必要做 … 不必要做 … lack of obligation:

Activity 3 Look at the two sentences and decide which explanation is correct. 1 We all know each other. We don’t need to worry about small talk. This means _____. a)it isn’t necessary to worry about it b)unfortunately we worry about it 2 The party is informal. You needn’t wear a tie. This means ________. a)we must not wear a tie b)we can wear a tie if we choose a b

1. Stop! You ____________ give yellow flowers to the host! It’s unlucky! 2. Don’t worry. You _____________________ eat anything you don’t like. mustn’t, can’t don’t have to, needn’t to Activity 4 Complete the sentences with verbs to express obligation or lack of obligation.

3. I’m sorry. You can’t leave. You ____________ wait until the prizes have been given. 4. ___I ______________take some food to the party? 5. You _______________________ take a gift to the host, but she will be very pleased if you do. must, have to Dohave to, need to don’t have to, don’t need to

Grammar didn’t need to do and needn’t have done

Discussion: Look at the picture below and share your ideas. You needn’t have run so quickly. Why did the man say it? 1.The other man was running too quickly. 2.The other man was running too slowly. 3.The other man was running quickly and it wasn’t necessary.

Observation Look at the sentences below, then find out the differences between them.  My lost umbrella was found, so I didn’t need to buy a new one. You needn't have written such a long essay.The teacher only asked for 300 words,and you have written 600 ．You needn't have written such a long essay.The teacher only asked for 300 words,and you have written 600 ．. didn’t need to do 表示那件事不必做而且实际上也没做。 needn’t have done 表示虽然那件事不必做但实际上却做了。

Activity 2 Read the sentence and decide which endings are possible. I didn’t need to buy a gift for my host family______. a)because I already had one b)so I didn’t get one c)so I bought one d)so I took it back and got a refund

Activity 3 Rewrite these sentences using needn’t have done. 1.It wasn’t necessary for you to bring some flowers! 2.Thank you for tidying the room– but it wasn’t necessary. 3.There was no need for you to buy the box of chocolates. 4.Why did you go to school? It’s Sunday! 5.Thank you for bringing the book to show me, but I already have it.

Answers: 1.You needn’t have brought some flowers. 2.You needn’t have tidied the room. 3.You needn’t have bought the box of chocolates. 4.You needn’t have gone to school. 5.You needn’t have brought the book to show me.

1.We brought some food to the party but there was too much, so we ___________________ (bring) any. 2. My friend spoke good Mandarin so I ____________________ (translate) the speech for him. needn’t have brought didn’t need to translate Complete the sentences using didn’t need to do or needn’t have done.

3. The office had already opened when we arrived so we _______________ (wait) outside in the street. 4. I got to the party at 6 p.m., but there was no one there. So I __________________ (arrive) so early. didn’t need to wait needn’t have arrived

5. I told the host all about my home town and then he told me he’d been there. I _______________ (tell) him anything. needn’t have told

1. 天要下雨了, 你没必要浇花。 It was going to rain. You didn’t need to water the flowers. 2. 昨天你本没必要去车站。 You needn’t have gone to the station yesterday. Translate

3. 你无需告诉他这一消息, 那只会使他 悲伤 。 You didn’t need to tell him the news; it just made him sad. 4. 如果我早知道火车站这么近, 我就用 不着打出租车了。 If I had known that the railway station was so near, I needn’t have taken a taxi.

1. The boss has given everyone a special holiday, so we _____ go to work tomorrow. ( 上海 2007 春 ) A. can’t B. mustn’t C. needn’t D. shouldn’t 2. —Must he come to sign this paper himself? —Yes, he _____. ( 广东 2006) A. need B. must C. may D. will 3. —Catherine, I have cleaned the room for you. —Thanks. You _____ it. I could manage it myself. ( 福建 2005) A. needn’t do B. needn’t have done C. mustn’t do D. shouldn’t have done

4. As you worked late yesterday, you _____ have come this morning. ( 陕西 2006) A. mayn’t B. can’t C. mustn’t D. needn’t 5. I _____ have bought all that wine — only three guests came. A. mustn’t B. needn’t C. may not D. wouldn’t