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 7. 现在完成时 (1) 现在完成时的句型结构 ①肯定句：主语+ have/has+ 过去分词 ②否定句：主语+ have/has+ not+过去分词 ③疑问句：Have/Has +主语+过去分词 (2) 现在完成时的用法 ①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： I’ve never been to Africa. Have you ever been to Tokyo? I’ve been there three times. ②. 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。 ③.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 6 years. /since 6 years ago/since 2003/ since I came to this city. It is/has been …+ since…. It’s been seven years since we last saw each other. It’s 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。 ④ 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 have finished your work. 比较：You can go home when you finish your work. (3) 过去分词的构成 ① 一般情况下在动词词尾后直接加-ed。 如： listen-listened, talk-talked ② 以不发音的字母e结尾的动词，直接加-d。 如： live-lived, hope-hoped ③ 以辅音字母加y接尾的动词，y变i，再加-ed. 如： worry-worried, hurry-hurried ④ 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 ⑤ 不规则变化 如： cut-cut-cut, come-came-come begin-began-begun, lend-lent-lent 本文来源：https://www.wddqw.com/doc/10a69b323968011ca300919d.html