精华版现在完成时讲解及练习附带答案VIP免费

现在完成时讲解 一、基本结构：主语+have/has+过去分词(done) ①肯定句：主语+have/has+过去分词+其他 ②否定句：主语+have/has+not+过去分词+其他 ③一般疑问句：Have/Has+主语+过去分词+其他 ④特殊疑问句：特殊疑问词+一般疑问句（have/has+主语+过去分词+其他） 二、用法 1） 现在完成时的"完成用法" 现在完成时用来表示现在之前已发生过或完成的动作或状态,但其结果却和现在有联系,也就是说,动作或状态发生在过去但它的影响现在还存在. He has turned off the light.他已把灯关了。(动作结束于过去，但说明的是现在的情况--灯现在不亮了。) I have spent all of my money.(含义是:现在我没有钱花了.) Jane has laid the table.(含义是:现在桌子已经摆好了.) 2） 现在完成时的"未完成用法" 指的是动作开始于过去某一时刻，一直延续到现在，或可能还要继续下去。这里的动词要用持续性动词。常与 for（+时间段）,since（+时间点）连用. Mary has been ill for three days. Mary has been ill since three days ago. 注意:1.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. 2.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等: He has already obtained a scholarship. I haven't seen much of him recently (lately). We have seen that film before. Have they found the missing child yet ? 3. 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. 4. 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. 5. 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...