Important sentence patterns:1. Its been six years since we last saw each other.2. This is the first time Ive visited your hometown.3. I feel very fortunate living here.4.Whats the climate like?5. The rent for an apartment is very high.Grammar: the present perfect tense Form: have/has done Usage:1. An action completed in the past but connected with the present situation. 2. An action beginning in the past and still continuing To denote continuous action or state (表持续的动作或状态表持续的动作或状态,常和常和since或或for引导的短语连用引导的短语连用).e.g. I have lived here for more than thirty years. I have been here since last October.To denote the past repeated action (表过去重复的动作表过去重复的动作,常和常和always ,often ,many times, every day等时间状语连等时间状语连用用).e.g. My father has always gone to work by bike. (我父亲一向是骑车上班我父亲一向是骑车上班) It has rained every day this week. (这个星期天天下雨这个星期天天下雨) To denote the future (表将来表将来, 尤尤用在时间状语从句中用在时间状语从句中)e.g. We are going after we have had breakfast. I will wait until he has written his letter. Cf: Tense: the past indefinite tenseUsage: a definite action completed in the past 1. -How long ago did you part from each other? -It _ five years since we said goodbye to each other.A.was B. would be C.had been D.has been2.-Who broke the glass? -Sorry. I_.A. have done B. did C. broke D.am3. - How long has he been away ,do you know? - Sorry ,I cant tell exactly when he _, though I know he has already been away. A.was leaving B. has left C. would leave D.left4.- How long _ at this job? - Since 1990. A. were you employed B. have you been employed C. had you been employed D.will you be employed 5.- How are you feeling today? - Oh, I _ as ill as I do now for a week. A. didnt feel B. wasnt feeling C. dont feel D. havent felt Study the following sentences:1.Who has opened the door?2.My watch has stopped3.They havent completed that experiment yet.4. He has already returned that book.(An action completed in the past but connected with the present situation)5. I have studied English for three years/since1999.6. He has worked in the company since he came to the city.7.So far he has written five books.(An action beginning in the past and still continuing)Find the mistakes in the following sentences and correct them:1.He has come back for three weeks.2.I have joined the army for ten years.(He came back three weeks ago.He has been back for three weeks.)(I have been in the army for ten years.I joined the army ten years ago.3. We achieved great success in the past few years.4.Perhaps she made several friends by now.5. When have you bought this computer?We have achieved great success in the past few years.Perhaps she has made several friends by now. When did you buy this computer?Sum up: The following words and phrases often appear in the present perfect tense.already, just, yet, lately, recently, ever, rarely, since, so far, up to now, by now, in the past ten years, during the past ten years, in the last few months, during the last few months1.Verbs to describe events that can continue over a period of time: Know, live, stay, remain2. Verbs to describe events that happen at a particular point of time: borrow, buy, give, leave ,open1. -_ leave at the end of this month. (2006北京北京) -I dont think you should do that until _ another job. A. Im going to; youd found B. Im going to; youve found C. Ill; youll find D. Ill; youd find2. Customers are asked to make sure that they _ the right change before leaving the shop. (2006重庆重庆)A. will give B. have been given C. have given D. will be given3. Although medical science _ control over several dangerous diseases, what worries us is that some of them are returning. (2006江江苏苏)A. achieved B. has achieved C. will achieve D. had achieved4. I wont tell the student the answer to the math problem until he _ on it for more than an hour. (2006湖湖北北)A. has been working B. will have worked C. will have been working D. had worked5. The construction of the two railway lines _ by now. (2006陕陕西西)A. has completed B. have completed C. have been completed D. has been completed6. My friend, who _ on the International Olympic Committee all his life, is retiring next month. (2006浙江浙江)A. served B. is serving C. had served D. has served7.They had been working on the program for almost one weeks before I joined them, and now we _on it as no good results _ so far. (2005 江苏江苏 )A. are still working , come out B. were still working , come out C. have worked , have come out D. are still working ,have come out 1)1)有人把窗户打破了。有人把窗户打破了。2) 2) 他到过许多国家。他到过许多国家。3) 3) 自从我来到这所学校，她一直自从我来到这所学校，她一直教我。教我。 Someone has broken the window.He has been to many countries.She has been teaching me since I came to this school.4) 4) 我有三个月没买过任何东西。我有三个月没买过任何东西。5) 5) 雨还没有停，你怎么能走呢？雨还没有停，你怎么能走呢？6) 6) 他们晚饭后经常下棋。他们晚饭后经常下棋。I havent bought anything for three months.How can you go before the rain has stopped ? They often play chess after they have had supper.7) 7) 直至近日，他将此书藏在一个神直至近日，他将此书藏在一个神秘的地方。秘的地方。8) 8) 我们过不了河，因为河水涨了。我们过不了河，因为河水涨了。Until recently he has hidden the book in a secret place. We cannot cross the river because the water has risen.