文档介绍：现在完成时
表示过去发生或已经完成的动作对现在造成的影响或结果,或从过去已经开始,持续到现在的动作或状态。
【常用时间状语】recently, lately, since+时间点, for+数字+时间名词, in the past few months/years等
【构成】肯定形式:have/has + done
否定形式:have/has + not +done
一般疑问句:have或has放于句首
B. 现在完成时的用法
1)现在完成时所表示的动作在说话之前已完成,而对现在有影响。
eg. The car has arrived. 车子来了。(结果:车子已在门口)
Someone has broken the window. 有人把窗户打破了。(结果:窗户仍破着)
区别:have been to, have gone to, have been in
have been to,表示去过某个地方,不过现在已经回来了
have gone to表示去了,但还没有回来,也许是在去的途中
have been in指的是在某个地方,从过去一直延续到现在
例如:你以前去过北京么?
例如:A: Is at home?
B: No,he is not in, (他去香港了)
2)现在完成时所表示的动作开始于过去,持续到现在,也许还会持续下去。常用for和since表示一段时间的状语或so far,now,today,this week (month,year)等表示包括现在时间在内的状语。
eg. He has studied English for 5 years.
He has studied English since 2001.
Now I have finished the work.
注意:表示短暂时间动作的词,e,go,die,marry,buy等的完成时不能与for,since等表示一段时间的词连用。用来持续的动作或状态或表过去重复的动作,如live,study,be,wait等,常和since(自从)或for(经历)引导的词语连用。
如:I have lived here for more than thirty 。
由非延续性动词到延续性动词的转换:
arrive →be here
begin(start)→be on
die →be dead
come back →be back
leave →be away
fall ill(sick, asleep)
→be ill(sick, asleep)
get up →be up
go out →be out
finish →be over
put on →wear 或be on
open →be open
join →be in
或be a member of…
close →be closed
go to school →be a student
borrow →keep
buy →have
catch(a cold)→ have(a cold)
get to know →know
begin to study →study