2017年社区生鲜电商O2O平台商业运营发展计划书方案.ppt

现在完成时
概述
现在完成时(Present perfect)过去发生并且已经完成的动作对现在造成影响或后果,过去某一时间开始并一直持续到现在的动作或状态。
句型
基本结构:主语+have/has+过去分词(done)
①肯定句:主语+have/has+时间状语+过去分词+其他.
②否定句:主语+have/has+not+过去分词+其他.
③一般疑问句:Have/Has+主语+过去分词+其他.
④特殊疑问句:特殊疑问词或词组+一般疑问句(have/has+主语+过去分词+其他)?
定义:在过去不确定的时间里发生的动作,但是结果对现在有影响。
用法
(1)现在完成时用来表示现在之前已发生过或完成的动作或状态,但其结果却和现在有联系,也就是说,动作或状态发生在过去但它的影响现在还存在.
I have spent all of my money.(含义是:现在我没有钱花了.)
Jane has laid the table.(含义是:现在桌子已经摆好了.)
Michael has been ill.(含义是:现在仍然很虚弱)
He has returned from abroad. (含义是:现在已在此地)
(2)现在完成时可以用来表示发生在过去某一时刻的,持续到现在的动作(用行为动词表示)或状态(be动词表示)常与for(+时间段),since(+时间点或过去时的句子)连用.
①for+时段
②since+过去一个时间点(译为:自从……以来)
③since+时段+ago
④since+从句(过去时)
●⑤It is+时段+since+从句(过去时)
Mary has been ill for three days.
I have lived here since 1998.
●注:瞬间动词(buy,die,join,lose……)不能直接与for since 连用。要改变动词
come/arrive/reach/get to-----be in
go out----be out
finish----be over
open----be open
die----be dead
………………
★
My brother has had(不能用has bought) this bike for almost four years.
★2、用keep或have代替borrow
I have kept(不能用have borrowed) the book for quite a few days.
★3、e
How long has your sister been a teacher?
★4、用have a cold代替catch a cold
Tom has had a cold since the day before yesterday.
★5、用wear代替put on
b)用“be+形容词”代终止性动词
1、be+married代marry 2、be+ill代fall (get) ill
3、be+dead代die 4、be+asleep代fall (get) asleep
5、be+awake代wake/wake up 6、be+gone代lose,die,sell,leave
7、be+open代open 8、be closed代close/shut
9、be+missing(gone,lost)代lose
c)用“be+副词”代终止性动词
1“be+on”代start,begin
2“be+up”代get up
3“be+back(to)”代return e back to,go back to
4“be here (there)”代come(arrive,reach,get) here或go (arrive,reach,get) there等等
d)用“be+介词短语”代终止性动词
1.“be in/at +地点”代替go to /come to
in the army 代替join the army
3.“be in/at +地点”代替move to
常用瞬间动词变延续性动词表:
1. have arrived at/in sw. got to/reached sw. come/gone/moved to sw.
→have been in sw./at…相应的介词
2. e/gone back/returned → have been back
3. e/gone out →have been out
4. have e → have been
5. have cl