英语语法讲解现在完成时讲解课件

语法讲解
现在完成时
ThePrentPerfectTen
现在完成时的构成
Ihavealreadybrushedmyteeth.
过去分词
肯定句:主语+have/has+done
否定句:主语+have/has+not+done
疑问句:Have/Has+主语+done
Yes,主+have/has.
No,主+haven’t/hasn’t.
Hehasfinishedhishomework.
Hehasnotfinishedhishomework.
Hashefinishedhishomework?
Yes,hehas./No,hehasn’t.
MyparentshavebeentotheUSA.
Myparentshaven’tbeentotheUSA.
HaveyourparentsbeentotheUSA?
Yes,theyhave./No,theyhaven’t.
过去分词的变化规则
1.直接加-ed,如:worked
2.不发音-e结尾,加d,如:hoped
3.辅音+y结尾的,把y变i加ed,如:carried
4.重读闭音节结尾,双写辅音字母+ed,如:stopped
过去分词的不规则形式
AAA型(三种形式都一样)
cost-cost-costhit-hit-hit
put-put-putread-read-read
ABB型(过去式与过去分词相同)
buy-bought-boughtcatch-caught-caught
find-found-foundhave-had-had
过去分词的不规则形式
ABA型(原形与过去分词相同)
come-came-come
become-became-become
ABC型(三种都不一样)
do-did-done
go-went-gone
take-took-taken
write-wrote-written
现在完成时的用法1
past
now
future
对现在有影响
Yesterday,theycleaned
theclassroom.
Now,theclassroomiscleanbecau
theyhavecleanedit.
用法1
强调过去发生的动作对现在产生的结果或影响。
1.Isawthisfilmlastweek.
Now,IknowthisfilmbecauIhaveenitbefore.
2.Ididmyhomeworkyesterday.
Now,IcangiveittotheteacherbecauIhavedoneit.
3.Shehadbreakfastinthemorning.
Now,sheisnothungrybecaushehashadbreakfast.
现在完成时的用法1
用法2:
过去发生的动作一直延续到现在。
past
now
future
Ibegantoteach
Englishatthis
schoolfive
yearsago.
Ihavetaught
Englishatthis
schoolforfiveyears.
现在完成时的用法2
1.Sheisadoctor.Shebegantoworkwhenshewas20.Now,sheis28.Shehasworkedforeightyears.
2.TheywenttoLondonlastSaturday.TodayisSaturday.TheyhavestayedinLondonsincelastSaturday.
现在完成时的用法2