现在完成时态结构(3页).doc

-现在完成时态结构-第 3 页定句：主语+have/has+过去分词否定句：主语+have/has not +过去分词疑问句：Have/Has+主语+过去分词7. 现在完成时(1) 现在完成时的句型结构肯定句：主语+ have/has+ 过去分词否定句：主语+ have/has+ not+过去分词疑问句：Have/Has +主语+过去分词(2) 现在完成时的用法表示到目前为止曾经有过的或未曾有过的经历和体验。常和never, ever, several times等连用。如：Ive never been to Africa.Have you ever been to Tokyo?Ive been there three times. 表示某动作从过去开始，现在刚刚完成，对现在有一定的影响。常与just, already, yet, so far等词语连用。如：He has just finished his new book.注意：just now用于过去时。.表示某动作从过去开始，一直持续到现在，可能还会持续下去。通常与 for或since连用。如：I have lived in Qingdao for 6years. /since 6 years ago/since 2003/since I came to this city.It is/has been + since.Its been seven years since we last saw each other.Its six years since he was a teacher.注意:for+一段时间，since后接一个过去的时间点或一般过去时的句子。 在表将来的时间状语和条件状语从句中代替将来完成时。如：You can go home when you havefinished your work.比较：You can go home when youfinish your work.(3) 过去分词的构成 一般情况下在动词词尾后直接加-ed。如：listen-listened, talk-talked 以不发音的字母e结尾的动词，直接加-d。1/2如：live-lived, hope-hoped 以辅音字母加y接尾的动词，y变i，再加-ed.如：worry-worried, hurry-hurried 以重读闭音节结尾，且结尾只有一个辅音字母的动词，双写辅音字母，再加-ed。如：drop-dropped, plan-planned, stop-stopped 不规则变化如：cut-cut-cut, come-came-comebegin-began-begun, lend-lent-lent