时态讲解：现在完成时1）现在完成时通常表示过去发生或已经完成的某一动作对现在造成的影响和结果。说话人强调的是该动作或状态对现在的结果或影响。 My daughter has just gone out. 我女儿刚出去。 Im sure weve met before. 我肯定我们以前见过面。 She has arrived. 她到了。2）表示开始于过去并持续到现在的动作或状态，往往和包括现在在内的表示一段时间的状语连用，如recently, already, just, lately, for, since,yet等。如：I havent heard from her these days. 这些日子我没有收到她的信。 We havent seen you recently. 最近我们没有见到你。They have been away for two years. 他们离开已经两年了。 She has been with us since Monday.3）. 现在完成时还可以用来表示过去的一个时间到现在这段时间内重复发生的动作. We have had four texts this semester. 6. have been to 和have gone to的区别have been to 强调“去过”，现已不在那里，如：He has been to the USA three times.他到美国去过三次。（过去“到美国”，现在已“不在美国”）have gone to主要强调的是“去了”，现在人不在说话的现场，如：-Wheres your mother? -你妈妈在哪？-She has gone to the hospital. -她去医院了。一 结构1.肯定句：主语+have/has+动词的过去分词+其他2.否定句：主语+have/has+not+动词的过去分词+其他3.一般疑问句：have/has+主语+动词的过去分词+其他 Yes, 主语+have/has. No , 主语+have/has+not4.特殊疑问句：特殊疑问词+have/has+主语+动词的过去分词+其他二 常和现在完成时一起连用的时间状语注意:.现在完成时不能单独与准确时间连用，(如表示过去的时间状语）如yesterday(morning、afternoon),last(morning、afternoon)等，除非与for, since连用.1.现在完成时往往同表示不确定的过去时间状语连用如already（肯定）, yet（否定，疑问）, just, before, recently, still, lately，Just, already, yet, ever, never, before, twice(重复性时间)， for+短时间， since+点时间， so far, how long 提问的疑问句中.He has already obtained a scholarship. I havent seen much of him recently (lately). We have seen that film before. Have they found the missing child yet ?2. 现在完成时常常与表示频度的时间状语连用,如ever, never, twice, several times等: Have you ever been to Beijing I have never heard Bunny say anything against her. I have used this pen only three times. It is still good. George has met that gentleman several times.3. 现在完成时还往往可以同包括现在时间在内的时间状语连用,如up to these few days/weeks/months/years, just, up to present(now), so far等: Peter has written six papers so far. Up to the present everything has been successful. 三 当现在完成时与表示短时间的时间状语连用时，谓语动词必须使用延续性动词。如果谓语动词是非延续性动词则转化为对应的延续性动词。 若不是和短时间连用，则不用转化。英语的行为动词有持续性动词和瞬间性动词之分，使用中应注意两者的区别。1. 持续性动词: 表示一个动作可以持续一段时间或更长时间。常见的study, play, do, read, learn, drive, write, clean , sleep, speak, talk, wait, fly, stay, sit, stand, lie, keep等。2. 瞬间性动词: 表示一个动作发生在一瞬间，非常短暂。亦称终止性动词。常见的-begin, start, finish, go, come, leave, find, get up, arrive, reach, get to, enter, hear, stop, open, close, become, buy, borrow, lend, happen, join, lose, renew, die, take away, put up, set out, put on, get on/off等3. 瞬间性动词在完成时中如要与表示持续一段时间的状语连用，通常用意思相当的持续性动词来替换He has been in the army/a soldier for three years. （他参军已有3年了。）不用has joined She has been up for quite some time. （她起床已有好久了。）不用has got up Has your brother been away from home for a long time? （离家已有好久了吗？）不用has left 常用瞬间动词相应持续性动词关系：1、gobe away 2、comebe here 3、come backbe back 4、leavebe away（be not here） 5、buyhave 6、borrowkeep 7、diebe dead 8、beginbe on 9、finishbe over 10、openbe open 11、closebe closed 12、losebe lost 13、get to knowknow 14、turn onbe on 15、get upbe up 16、sit downsit/beseated 17、joinbe in（）或be amember 18、becomebe动词不规则变化分类记忆表一、ABB型（过去分词与过去式一样）1、sleep-sleptsweepsweptkeepkept2、burn-burntmeanmeant3、bringbroughtfightfoughtbuyboughtteachtaughtthinkthoughtcatchcaught4、lendlentbuild-builtsendsentspendspentfindfoundhold-held5、feel-feltsmellsmeltmeetmetgetgotsitsatleaveleftlose-lost6、sellsoldtell-toldsay-saidstand-stoodwin-wonunderstandunderstoodmake-made二、ABC型（过去分词=动词原形+n/en） 1、blow blew -blown grow -grew grown know -knew known throw -threw -thrown draw -drew drawn show -showed -shown 2、drive -drove -driven rise rose -risen give -gave -given see -saw -seen take -took -taken 3、mistake -mistook -mistaken eat -ate -eaten beat beat -beaten 4、fall-fell -fallen ride -rode -riden write -wrote -writen 三、 ABC型（过去分词=过去式+n）break-broke-broken choose-chose-chosen speak -spoke -spoken 四、 ABC型（动词原形、过去式、过去分词的元音字母呈i-a-u 变化） begin -began -begun drink -drank -drunk ring -rang rung 五、 ABC型（原形、过去式、过去分词各不一样） am/ is -was -been are -were -been fly -flew-flown lie -lay -lain do -did -done go -went -gone wear -wore -worn 六、 ABA型（过去分词与原形一样）become -became -become come -came -come run -ran -run 七、 AAA型 cut hit hurt let put read 八、 ABB型（两种形式）hang -hung / hanged -hung / hanged learn -learned / learnt -learned / learnt shine -shone / shined -shone / shined smell -smelt / smelled -smelt /smelled4. 瞬间动词的否定形式可以与表示一段时间的状语连用例如：I havent seen you for a long time.