4.现在完成时和一般过去时的区别

现在完成时所表明的是过去发生的动作对现在的影响,强调的是现在的情况,不可以和表示过去的时间状语yesterday,in 1991,three days ago last time,last night等连用一般过去时表明的是过去发生的事实,和现在不发生关系.　　　　　　

3.现在完成时中been to,gone to和been in/at been to去过某地,表示某人的一种经历,可以和once,twice,already,ever,never等连用.　　 eg. She has been to Shanghai twice. (表示目前人在这里)　　　　　　　

gone to 去某地了,说话时某人已离开此地,在去某地的途中或已在某地,

eg. She has gone to Shanghai。 (表示现在她人不在这里)　　　　　　　

been in/at 逗留在某地(已经一段时间).常和for ten days,since I came here等连用.

eg. She has been in Shanghai since she moved there.　　　　　　　　　

2.初中英语课本中常见终止性动词有:leave, go, come, arrive, begin, buy, borrow, die, join, become等.终止性动词要表示持续时, 可用以下方法:　　　　　　　　

⑴.将时间状语改为时间段 + ago,句中谓语动词用一般过去时.

eg.我弟弟参军两年了. My brother joined the army two years ago.　　　　　　　

⑵.若保留for+时间段,since+时间点/从句, 或用在 how long 句型中,则需将终止性动词改为相应的状态动词或延续性动词　　　　　　　　　　　

常见终止性动词与延续性动词(或状态动词)的对应关系如下

come/go/arrive/get/reach/move------be in/at open-----be open

die------be dead close----be closed become---be borrow---keep　 begin/start-----be on put on----wear

leave-----be away (from) buy-----have fall asleep----be asleep

end/finish-----be over catch a cold-----have a cold

join the army----be in the army be a soldier　　 join the Party----be in the Party be a Party member

→My brother has been in the army for two years.　 →My brother has been a soldier for two years.

2.表示过去发生的动作或存在的状态,一直持续到现在,也许还将继续下去,可以和表示从过去某一时刻延续到现在的一段时间的状语连用,即for +时间段,since+时间点/从句, in the last ten years等,谓语只可用延续性动词.

　 解析：　 1.英语动词根据词义可分为两种,一种是延续性的,一种是终止性的,终止性动词(也可称为非延续性动词,瞬间动词,或点动词),如begin,start,die,buy,leave, come等,表示动作的发生与结束于一瞬间完成,不能再延续,所以它的现在完成时不能和表示延续的时间状语连用,即不能与表示一段时间的状语,for+时间段, since+时间点/从句连用,也不能用在how long引导的特殊疑问句中.

　eg. I've left Shanghai for three days.(×)　　 I've been away from Shanghai for three days.( √ ).

I left Shanghai three days ago. ( √ )　　 It is /has been three days since I left Shanghai.( √ )　

6.Mr and Mrs Green____(travel)to the south of China next week,aren't they? 7.I___(not see)the film with you because I've seen it already.　 8.He told us that he_____(stay)here till the next week.　　 9.I_____(lose)my pen this morning. I haven't found it yet.

动词的时态(下)

G:现在完成时棗表示到目前为止已经完成，并对现在留下某种后果和影响的动作。

结构：助动词have/has + 动词的过去分词

用法: 1.表示过去发生的某一动作对现在造成的影响或结果,常与一些时间状语,如:already, yet, ever, never, just, before, once,twice等连用,也可以和包括现在在内的时间状语,如these days,today,this year,so far等连用.eg.I have already posted the letter. (信已经不在我这儿了)　　　　　　 　　　

4.The sky is black. It ____ (rain), I'm afraid.　　 5.If it ___(not snow)tomorrow,we'll go skating　

2.He'll write to you as soon as he _____ (arrive ) in Hainan.　 3.The students of Class One ___(have)a meeting from three to five yesterday afternnon.

1.The Chinese people ____(work) hard to make their country stronger and more beautiful.

5.Lucy said it ___________ (rain) later on.

思考题:

4.The bell for the class rang while they ___________ (play) on the playground.