时态(Tense)是表示行为优质PPT.ppt

1、0例：He always helps others.（他总是帮助别人。）D）客观事实和普遍真理。尤其要注意，如果前后文不是一般现在时，则无法保持主句、从句时态一致。3.Once environmental damage _,it takes many years for the system to recover.A）has done B）is to do C）does D）is done,E）表示一个按规定、计划或安排要发生的动作，（仅限于某些表示“来、去、动、停、开始、结束、继续”等的动词）可以与表示未来时间的状语搭配使用。常见的用法是：飞机、火车、轮船、汽车等定期定点运行的交通方式。例：

2、The next train leaves at 3 oclock this afternoon.How often does this shuttle bus run?F）在时间和条件状语从句里经常用一般现在（有时也用现在完成时）表示将来事情。When you have finished the report,I will have waited for about 3 hours.（等你完成这份报告的时候，我就已经等了将近3个小时了。）4.Government cannot operate effectively _ it is free from such interference.A）

3、so long as B）so that C）unless D）because,有些表示状态和感觉的动词如:be,love,like,hate,want,hope,need,prefer,wish,know,understand,remember,believe,recognize,guess,suppose,mean,belong,think,feel,envy,doubt,remain,consist,contain,seem,look,see,fit,suit,owe,own,hear,find,suggest,propose,allow,show,prove,mind,have,sou

4、nd,taste,matter,require,possess,desire.常用于一般现在时Eg:I feel sharp pain in my chest.The soup contains too much salt.You see what I mean?We greatly rejoice over your success.The coat fits you very well.It doesnt matter.,How do you find your key?Does it hurt?I regret to say I dont agree with you.The food

5、taste hot.The food cost 4,but I only paid 3 so I still owe 1.He owes me five dollars.I owe you an apology.We owe our parents a lot.AppreciateShe owes her success to good luck.I propose to go on Tuesday.He possesses two cars.She possesses some interesting pictures.,有些表示动作的动词间或可由于这一时态,表示现刻的动作,由于动作持续时间

6、极短,用进行时极不自然.Eg:I send you my best wishes.I apologize.I accept your advice.Now I extend my heartfelt thanks to you.I advise you to be cautious.We thank you for your kind invitation.I enclose a form of application.I enclose a check for$400.我附上一张400美元的支票。Enclosure=inclosure 附件,2.现在进行时（be doing）的用法5.The

7、 fifth generation computers,with artificial intelligence,_ and perfected now.A）developed B）have developed C）are being developed D）will have been developed3.现在完成时（have done）1）用法：A）表示动作到现在为止已经完成或刚刚完成。6：I bought a new house,but I _ my old one yet,so at the moment I have two houses.A）didnt sell B）sold C

8、）havent sold D）would sell,B）表示从过去某时刻开始，持续到现在的动作或情况，并且有可能会继续延续下去。此时经常用延续性动词。时间状语常用since加一个过去的时间点，或for加一段时间，或by加一个现在时间。7.Great as Newton was,many of his ideas _ today and are being modified by the work of scientists of our timeA）are to challenge C）have been challengedB）may be challenged D）are challeng

9、ingC）表示发生在过去，但对现在仍有影响的动作或情况。通常用点动词，如：arrive,begin,find,give,lose等。John has broken his left leg.,2）注意事项A）现在完成时是联系过去和现在的纽带。现在完成时和过去时的区别在于：现在完成时强调动作的动态，或受动态的影响，是动态的结果，对现在有影响；过去时只表示过去的某个具体时间里发生的动作，与现在没有联系。He worked in that hospital for 8 years.（这只是讲述一个过去的事实，他现在已经不在那家医院了。）He has worked in that hospital f

10、or 8 years.（表示他从过去开始工作，一直工作到现在，现在仍在那家医院工作。）,B）因为含有for加一段时间或since加一个时间点这样的时间状语的完成时，有动态和延续性的特点，所以不能使用终端动词或瞬间动词。My sister has been married for 5 years.（过去分词做表语表示状态，可以延续）My sister has married.Dont disturb her.（终端动词 C）在“this is the first/second/third time that”句型里要求用完成时。This is the second time that the p

11、roducts of our company have been shown in the International Exhibition.,D）句型“It is/has beensince”所使用的两种时态都正确。It is/has been 10 years since I last saw him.（从我上次见到他以来已经10年了。）E）在“no sooner-than”、“hardly/scarcely when”、“before”、“prior to”等句型中，主句要求完成时。I havent met that professor prior to today.4.现在完成进行时（

12、have been doing）1）用法：表示某一动作开始于过去某一时间，延续或重复地出现至今，或将继续延续至将来。We have been working on this project for over a month now.（到目前为止，我们一直在处理那个项目，已经花了一个多月时间了。）,2）注意事项：与现在完成时相比，现在完成进行时更强调：在从过去到现在的时间里，动作或状态一直持续或一直反复出现。8.It seems oil _ from this pipe for some time.Well have to take the machine apart to put it rig

13、ht.A）had leaked B）is leaking C）leaked D）has been leaking,Past tense,5.一般过去时1）用法：A）表示过去某个时间发生的动作或情况。9.I decided to go to the library as soon as I _.A）finish what I did B）finished what I didC）would finish what I was doing D）finished what I was doing“我决定一做完手头的工作就去图书馆”。本题首先要判断的是as soon as（一就）引出的时间状语从句中谓

14、语动词的时态。从句中的动作“做完手头的工作”是预计将要发生的动作，而去句的谓语动词用的是过去时。在这种场合，从句中通常用一般过去时，而不用过去将来时。所以选项A和C不可能是答案。句子指的是“完成正在做的工作”，do要用进行式。因此选项D才是答案,B）表示过去习惯性动作。特别是由would/used to do表达的句型，本身表示的就是过去时。The old man would sit on a bench in the quiet park and look at others for hours without doing anything or talking to anybody.（过去

15、常常）He used to visit his mother once a week.C）有时可代替一般现在时，表达一种婉转、客气、礼貌、商量的语气。I wanted to ask you if I could borrow your car?Would you mind my sitting here?,2）注意事项：A）注意时间状语的搭配。一般过去时的时间状语应该是表示过去某个时间的词或词组，如：yesterday,last month,in 1999,two days ago等，绝对不可与recently,in the past 10 years,this month等连用，因为这样的时间状语都与现在有关系，应该用现在完成时或一般现在时。B）used to do的否定形式和疑问形式很特别：你怎么写都正确。以否定形式为例：used not to do,didnt used to do,didnt use