文档介绍：现在完成时
一、其构成
"助动词have (has) +动词过去分词"构成现在完成时。如:
1. Kate's never seen Chinese films,____ ?  A. hasn't she B. has she C. isn't she D. is she
析:陈述句部分含否定词never,简略问句部分要用肯定式,又因Kate's是Kate has的缩写,故选B。
2. His uncle has already posted the photos to him. (改为否定句)
His uncle ______ posted the photos to him ______.
析:already常用在肯定句中,yet常用在否定句、疑问句中,故填hasn't, yet。
3. -Ann has gone to Shanghai. -So ______her parents.   A. has B. had C. did D. have
析:"so+助/系/情态动词+主语"结构中的动词形式应与前句结构中动词形式保持一致,又后句的主语为her parents是复数,故选D。
二、其用法与标志词
(一)当句中有never, ever, just, already, yet, before等时,常用现在完成时。如:
1. -Mum, may I go out and play basketball? -___________ your homework yet?
A. Do; finish   B. Are; finishing   C. Did; finish    D. Have; finished
2. -______ you ______anywhere before? -Yes, but I can't remember where I______
A. Did; surf; surfed         B. Have; surfed; surfed
C. Did; surf; have surfed    D. Have; surfed; have surfed
析:据yet和before可知,应用现在完成时,故1题选D,2题选D。
(二)当句中有"for +段时间"或"since +点时间"等时,主句常用现在完成时,谓语动词必须是延续性动词,若是非延续性动词,要改为延续性动词或表状态的词(短语)。如:
1. His brother has been to Stone Forest twice______he came to Yunnan.
A. after   B. before    C. since     D. for
析:主句用的是现在完成时,而从句用的是一般过去时,故选C。
2. Tom______the CD player for two weeks.
A. has lent    B. has borrowed    C. has bought     D. has had
析:A、B、C均为非延续性动词,在肯定句中不与表"段时间"的短语连用,故选D。
3. I______a letter from him since he left.
A. d