牛津英语8B Unit 1 Past and present (Grammar1)(江苏省徐州市)

课件17张PPT。 8B Unit 1
Past and
presentYunhe Middle School
Zhou Haijun Unit 1 Past and present GrammarⅠ Present perfect tense一、现在完成时谓语动词的定义：A.现在完成时态表示动作开始于过去某一时刻，一直延续到现在，或可能还要继续下去。
e.g. 1.He has lived here since 1978.
自从1978年以来，他一直住在这儿。
(动作起始于1978年，一直住到现在,可能还
要继续住下去。)
2. I have been in the army for more than 5 years.
我在部队已经呆了五年多了。
(动作开始于5年前，一直延续至今，有可能还
要继续下去。) B.现在完成时态表示动作发生在过去某一时刻并已结束，但该动作对现在产生了影响，与现在情况具有因果关系。
e.g. 1.He has turned off the light.
他已把灯关了。
( 动作结束于过去，但说明的是现在的情
况--灯现在不亮了。)
2.She has gone.
她走了。 (动作是过去发生的，而对现在所造成的
结果是她不在这里了。)
二、现在完成时谓语动词的构成： have/has+vedI have finished the composition already.He has learned English for three years.其中have/has为助动词，
ved为动词的过去分词。We make statements and negative statements
using the present perfect tense like this.We ask and answer questions using the
present perfect tense like this .过去分词的构成一、规则变化1、直接加 –ed looked watched
2、以不发音的e结尾的，加 –d changed
moved
3、以辅音字母加y结尾的，变y为i，加-ed
studied carried
4、重读闭音节，一元加一辅，双写辅音字
母，加-ed planned dropped stopped二、不规则变化见课本第121页。写出下列动词的过去分词，同时熟记。
1. teach ________ 2. bring ________
3. get __________ 4. know ________
5. grow_________ 6. find__________
7. hold _________ 8. show________
9. keep_________ 10. leave_______
11. lose_________ 12. run_________
13. swim________ 14. drive_______
15. begin_______ 16.write ________句型转换按要求改写下面的句子1.They have finished their homework.
(改为一般疑问句，并做肯定回答)
2.Mr. and Mrs. Li have come back.(改为否定句)
3.John has played this computer game
a few times.(改为否定句)
4.We have seen that film.
(改为一般疑问句，并做否定回答)
5.Mr. Dong has repaired over ten bikes
since last Monday. (改为否定句)I ________ (do) my homework already.
He _____________(not finished) his homework yet.
____you ever _____(be) to Beijing?
We ______ never ______ (see) such an exciting match before.
Mother _____ just _______(clean) the house. Please don’t come in.
They _____________(practice) this dialogue twice.have donehas not finishedHavebeenhaveseenhascleanedhave practiced用现在完成时态完成下面的句子：现在完成时与一般过去时的区别 1. 一般过去时表示过去某个时间发生的事、存在的状态或经常发生的动作。说话的侧重点只在于陈述一件过去的事情，不强调对"现在"产生的影响。如：
He visited Guilin in 1998.
他1998年参观过桂林。(只说明去桂林的时间)
2. 现在完成时表示动作发生在过去，对现在造成了影响或产生了结果。不与确定的过去时间状语连用。如：
Jill has bought a new computer.
吉尔买了一台新电脑。(着重点是现在有了一台新电脑)3. 两种时态的区分
　(1)一般过去时的谓语动词用过去式，而现在完成时的谓语基本构成是“助动词have /has +过去分词”。如：
The film started at 7 o’clock.
He has been a teacher for many years.
　(2) 一般过去时通常与表示过去的时间状语连用。如：yesterday, last week, two years ago, just now, in 2002等；而现在完成时则常与just, already, ever, never等副词和these days, this week, since..., for...等表示一段时间的状语连用。看看以下的几组句子，有什么区别？
① (A) Have you seen the film?
(B) Did you see the film?
[说明] 你看过这部电影吗？(A)句强调的是被问者对剧情是否了解；(B)句强调的是看这部电影的动作是否发生过，并不强调是否知道其内容。
② (A) How has he done it? 　
(B) How did he do it?
[说明]他是怎么做的这件事？(A)句强调的是他做这件事的方式对现在产生了某种影响；(B)句单纯的询问做这件事的方式。 (??? )1. A: __ you __ the football match yesterday? B: Yes, I did. It was great.??????? A. Did; see???????? B. Have; seen???????
C. Will; see?????? D. Were; seen(??? )2. A: Why not go to see the dolphin show with
me? B: No, let’s go home.??? Because I ______it
twice . A. saw????B. will see??C. see???D. have seen(??? )3. A: _____ you at home yesterday evening? B: Yes, I ______ with my mother. A. Were ; were????? B. Was ; was??????
C. Were ; was???? D. Was ; wereADC (??? )4. Everyone except Tom and Jane ______
there when the meeting began. A .are???? B .is???? C .was???? D .were(??? )5. My mother_______the windows already,
so the room looks much brighter. A. has cleaned???? B. had cleaned
C. is cleaning????? D. will clean (? ??)6. A: _____you ____your homework yet? B: Yes. I____ it a moment ago. A. Did;?? do;?? finished??????????
B. Have;?? done;?? have finished C. Have;?? done;?? finished???????
D. will;?? do;?? finishCACGoodbye！Thank you!