1、Unit 1 Past and present GrammarTeaching aims:Learn the use of the present perfect tense. Step 1. RevisionAnswer some questions about the conversation between Mr Chen and Millie.Model 1:Has Sunshine Town changed a lot? Yes, it has.Model 2:Have Mr Chen and his wife moved out of the town? No, they have
2、nt.1. Has the government built a new park? 2. Have most of Mr Chens old friends moved away?3. Has it become impossible for them to see each other as often as before?4. Have Mr Chen and his wife decided to move out of the town?Step 2. The present perfect tense1. We use the present perfect tense to ta
3、lk about actions that started in the past and continue to the present.来源:学优高考网e.g. I have lived here sin ce I was born.She has worked in this factory for nine years.2. We use the present perfect tense to talk about an action that happened in the past an d have a connection with the present. e .g. Ed
4、die has just eaten Hobos food. （Eddie ate the food, and now Hobo has nothin g to eat.)I have already seen the fil m?(I saw the f ilm in t he past and now I still remember something about the film.)3. We also use the present perfect tense to talk about how many times an action has happened till now.e
5、.g. I have already read this book many times. Mr Chen has been to the USA twice.4. We make positive statements in the present perfect tense like this:I / You/ We / They have He / She / It hasarrived.5. We make negative statements in the present perfect tense like this:I / You/ We / They have He / Sh
6、e / It hasnot arrived.6. We ask and answer questions using the present perfect tense like this:Have I / you/ we / theyHas he / she / it Yes, I / you/ we / theyhe / she / it No, I / you/ we / theyarrived?he / she / it 7. We form the past participles of some regular verbs by adding ed, just as what we
7、 do to form the simple past tense of these verbs:Most verbs+ed finish finishedVerbs ending in -e +d change changedVerbs ending in a consonant +y -y +ied carry carriedShort verbs ending in a vowel + a consonant double the consonant +edstop stopped8. We form the past participle of irregular verbs diff
8、erently. Here are some examples:No change comecome hurt hurtChange the vowel hold held win wonChange the consonant lendlent build builtChange the vowel(s) and the consonant(s)catch caught keep kept forget forgotten tell toldOthers be been have had fall fallen fly flowndraw drawn see seenStep 3 A sho
9、rt testWrite the past participles of the verbs below. borrow plan sayhope cry growmake send hitget watch enjoyComplete the sentences below using the present perfect tense. 1 They _ (finish) th eir homework already.2 John _ never _ (visit) China.3 Mr Li _ (repair) over ten bicycles since Monday. 4 We
10、 _ (not see) each other for years.5 My parents _ (not come) back yet.6 Our teacher _ (teach) us a lot about the history of China.Complete the conversation. Use the correct form of the verbs in brackets.Millie: _ you _ (see) any films recently, Sandy?Sandy: No, I havent. What about you?Millie: I _ (s
11、ee) one last Saturday. Sandy: Whats it about?Millie: Its about the changes in Beijing over the past century. From this film, I _ _ (learn) more about Beijings past and present.Sandy: Oh, I think I _ (hear) about the film. Do you plan to see it again?Millie: Yes, Id like to.Step 4 Summary一、现在完成时的构成：1
12、. 现在完成时的肯定句句型： 主语 + have /has +过去分词 e. g. He has lived in Beijing for ten years.I have finished my homework.2. 现在完成时的否定句句型：主语 + have/has+ not+过去分词 e.g. I have not seen the movie yet.He hasnt been to Beijing since then.3. 现在完成时一般疑问句的构成：Have/ Has + 主语+ 过去分词?Yes, 主语+ have/ has.No, 主语+ havent/ hasnt.e.g
13、. Have you finished your homework yet?Yes, I have. / No, I havent. havent =have not hasnt = has notIve = I have Hes = He has二、用法：以下两种情况应用现在完成时：1. 过去发生的动作或状态一直持续到现在。He has lived here since he came to Nanjing. 2. 过去完成的动作，但强调这个过去完成的动作对现在有一定的影响或产生某种结果 ：I h ave seen t hat film already. (I saw it in the p
14、ast and now I can still remember something about the film.) 一般过去时只用来表示过去发生了某事，并不能表明对现在产生了什么影响。e.g. He lost his mobile phone yesterday. 他昨天丢失的手机。(We dont know whether he has found it or not.) He has lost mobile phone already. 他已经把手机丢失了。（He cant use it right now.)三、判断方法：1. 依据用法，结合句意判断。如：他在这所学校教书有三年了。He has taught at this school for 3 years.2. 依据一些副词或时间状语判断。现在完成时常和 already, ever, just, never, recently, yet 等副词，以及 since, for 引导的时间状语连用。Have they arrived yet? already “已经”常用于肯定句中，yet “还，仍然，已经”，常用于否定句和疑问句中。Homework1. Review the summary on present perfect tense.2. Finish the exercises on the workbook.
