1、Unit3BacktothepastGrammarPresentperfecttensen Go over the news story on Page 2 and find the sentences using the present perfect tense.nPlease explain why the tense is used in these sentences.n The disappearance of Justin(make)Kelly very unhappy.has made We use the present perfect tense to talk about
2、 things that happened in the recent past,but are connected to the present.The uses of the present perfect tense n I(not see)Justin since last Friday night.nhave not seenWe also use the present perfect tense to talk about something that started in the past,and is still happening now.Complete the foll
3、owing sentences with the proper tense.n 1 We(study)English for about five years.n 2 They(live)in the south since their daughter was born.n 3 I(read)your article three times.Its well written.n 4 The student(finish)her homework already.n 5 Eric(go)back to his hometown today.n 6 The police (just finish
4、)searching the area.have studiedhave livedhave readhas finishedhas gonehave just finishedn We use the present perfect tense when the exact time of an action is not clear or important.We use it with time expressions such as:already ever for just lately never recently since yet already,yet;for,sincen
5、We usealreadyfor affirmative statements and yetfor negative statements.n We use for+a period of time and since+a point in time.n He has just gone out.(=He went out a few minutes ago.)n We use the present perfect tense here to tell others that he isnt here now.n I have just heard the news.(Now I know
6、 the news.)We use the present perfect tense to talk about actions that were completed only a short time ago.In this case,just is used.Pay attention to the position of just.n We can also use the present perfect tense for repeated actions,that is,we use the present perfect tense with the time expressi
7、ons once/twice/three timesn Tom has rung up three times this morning.(Now it is still in the morning.)n Tom rang up three times this morning.(Now it is not still in the morning.)n Actions occurring in an incomplete period might be indicated by today or this morning/afternoon/evening/week/month/year/
8、centuryor all day/night/week,all the time,always etc.n Look at the following sentences and point out what tense or tenses are used in them and the reasons why they are used.n 1 We have studied English for about five years.We began to study it five years ago.n 2 They moved to the south in 1990 and ha
9、ve livedthere since then.n 3 Eric left home last year and has just come back.n 4 Justin has been away from home for several days.He disappeared last Friday.n 5 They bought this house three years ago and they have lived here since then.6 My brother went to see my grandpa last week.He has visited him
10、three times this month.The present perfect tense and the past simple tensen 1 you my pen?Yes,I it on your desk just now.(see)n 2 you dinner?Yes,I it with Mary.(have)n 3 the postman yet this morning?Did the postman come this morning?(come)5 I him for a long time.Hello!I(not)you were here in Nanjing.H
11、ow long have you been here?(know)nHave seensawHave hadhadHave comehave knowndidnt known The present perfect tense is normally used for an action which lasts throughout an incomplete period,but with the past simple tense,we use time expressions which a fixed point in the past.n c.f.n We havent seen J
12、ustin for a week.(He is still missing.)n Justin disappeared last week.(It may mean that this week Justin is here.)n He has smoked since he left school.(He still smokes.)n He smoked for six months.(It means that he stopped smoking then.n Sometimes,however,the action finishes at the time of speaking.n
13、 It has been very cold lately but its just beginning to get warmer.n On meeting someone,you may say:I havent seen you for ages.(But I see you now.)n For a past action whose time is not definite and often has a result in the present.1 Tom has had a bad car crash.(Hes probably still in hospital now.)T
14、om had a bad car crash.(But hes probably out of hospital now.)2 The lift has broken down.(We have to use the stairs.)The lift broke down.(But its probably working again now.)n Read the diary entry and then complete it using the correct forms of the verbs in brackets.n(2)saw(3)has visited(4)loves(5)h
15、asnt visited(6)has swum(7)has never met(8)has dived(9)has found(10)hasnt found (11)Has,been n Present perfect continuous tenseThe uses of the Present perfect continuous tensen 1 I for an hour and he still hasnt turned up.(wait)n 2 Im so sorry Im late.you long?n We sometimes use the Present perfect c
16、ontinuous tense to talk about actions that started in the past and are still continuing,or have just finished but are still connected to the present in some way.have been waitingHave been waitingn Go over Points 1 and 2 on page 9.The form of the Present perfect continuous tensen We form the present
17、perfect continuous tense with have/has beenand the present participle of the verb.n Answers:(2)have been talking(3)have been taking(4)have been watching n(5)have seen(6)have been writing n Present perfect or present perfect continuous tense?n Li Jia has reada book about Stonehenge.n Li Jia has been
18、reading a book about Stonehenge.n In the first sentence,it means the action read isnt still continuing,and Li Jia knows what the book is about now,but in the second sentence,it means the action read is still continuing.n c.f.Ive cleaned the house.n Ive been cleaning the house.n Read Point 1 on page
19、10.n I Egypt twice this month.(visit)n I Egypt for two months.(tour)n The present perfect continuous tense cant be used with time expressions such as twice or how many times,because in this tense the action is continuous,not stopped and started again.n We can use the present perfect tense for repeat
20、ed actions,and the present perfect continuous tense for non-stop actions.have visited have been touringhow many times/how long n have you swum in the lake?nhave you been swimming in the lake?n We usually use the present perfect tense to ask questions beginning with how many/much,and the present perf
21、ect continuous tense to ask questions beginning with how long.How many timesHow longA state verb or an action verb n I have had this camera for five years.(state verb)n I have takenphotos of UFOs with this camera.(action verb)n I have been taking photos of UFOs with this camera.(action verb)n An act
22、ion means something happening or changing.A state means something staying the same.Some examples of action verbs are do,go,and play.Some examples of state verbs are like,know and exist.n A state verb doesnt mean an action,so it cant be used in a continuous tense.n Theyve always had a big garden.n Ho
23、w long have you known each other?n Hes beenin hospital since his accident.n Ive never visited Paris.n Ive already been to Paris.n always,never,yet,already and ever cant be used in a continuous tense.n I have not been sleeping well since I returned home.n Ive been waiting for an hour.n We can use for
24、 and since with the the present perfect continuous tense.n Answers on page 11n A(1)heard(2)been doing(3)been researching(4)been doing(5)started(6)done(7)read(8)found(9)started(10)been doing (11)been making n Sample answersn B 1 He has been waiting at an underground station.n2 They have been travelin
25、g in an UFO.It looks like a saucer.n3 They probably have talked to animals or plants on the earth as well as creatures on other plants.n4 They have visited Mars,Venus,Jupiter and some other planets.n How long have you learnt English?Or n How long haveyou been learningEnglish?n It has snowed for a lo
26、ng time.n It has been snowing for a long time.Both present perfect tense and present perfect continuous tensen An action which began in the past and is still continuing or has only just finished can,with certain verbs,be expressed by either the present perfect orpresent perfect continuous.Verbs which can be used in this way include expect,hope,learn,lie,live,sleep,sit,study,wait,want,rain,etc.n Homework n Part C1 and C2 on page 88 in Workbook n Prepare Task
