新概念英语第二册Lesson5语法.doc

Lesson5语法：现在完成时与一般过去时的区别
过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；
现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。2）过去时常与具体的时间状语连用，而现在完成时通常与模糊的时间状语连用，或无时间状语。一般过去时的时间状语:yesterday,lastweek，…ago,in1980,inOctober,justnow,具体的时间状语共同的时间状语:thismorning,tonight,thisApril,now,once，before,already,recently，lately现在完成时的时间状语for,since,sofar,ever,never,just,yet,till/until,uptonow,inpastyears,always,不确定的时间状语
注意：句子中如有过去时的时间副词（如yesterday,last,week,in1960）时，不能使用现在完成时，要用过去时。（错）Tomhaswrittenalettertohisparentslastnight.（对）Tomwrotealettertohisparentslastnight.
3）现在完成时可表示持续到现在的动作或状态，动词一般是延续性的，如live,teach,learn,work,study,know.过去时常用的非持续性动词有come,go,leave,start,die,finish,become,getmarried等。例：Isawthisfilmyesterday.（强调看的动作发生过了。）Ihaveseenthisfilm.（强调对现在的影响，电影的内容已经知道了。）Whydidyougetupsoearly?（强调起床的动作已发生过了。）Whohasn'thandedinhispaper?（强调有卷子，可能为不公平竞争。）ShehasreturnedfromParis.她已从巴黎回来了。Shereturnedyesterday.她是昨天回来了。HehasbeenintheLeagueforthreeyears.(在团内的状态可延续)HehasbeenaLeaguememberforthreeyears.(是团员的状态可持续)HejoinedtheLeaguethreeyearsago.(三年前入团，joined为短暂行为。)Ihavefinishedmyhomeworknow.---WillsomebodygoandgetDr.White?---He'salreadybeensentfor.
练习:用一般过去时或现在完成时填空：
1._________you________(have)lunch?Yes,Ihave.
When__________you_________(have)it?I___________(have)itat12:00.
2.___________you___________(write)alettertoyourauntyet?
Yes,I_________.I___________(write)onelastweek.
3.__________he_____________(finish)hishomework?Notyet.
4.___________theyever__________(be)abroad?Yes,justonce.
5.Yourfather___________just__________(finish)hiswork.
6.Yourfather___________(finish)hisworkjustnow.
7.LasttermI___________(learn)manyEnglishwords.
8.They______________(notread)theinterestingbooksyet.
9.He_________never_________(go)tothesciencemuseum.
10.__________youever__________(drink)coke?
11._________she_________(practice)herguitaryesterday?No,she_________.
12.________(be)yourmotherasalesassistantlastyear?No.she__________.
13.Myfriend,Carol,________(study)forthemathtestand________(practice)Englishlastnight.
14.Inthepast，there________（be）nopeopleinthisp