现在完成时和过去完成时现在完成时现在完成时，表示过去发生并且已经完成的动作对现在造成影响或后果；过去某一时间开始并一直持续到现在并且有可能还会持续的动作或状态。基本结构：主语+have/has+动词的过去分词(p.p)（V-ed） 肯定句：主语+have/has+动词的过去分词(p.p)（V-ed）+宾语. He has finished it. They have worked it out.否定句：主语+have/has+not+动词的过去分词(p.p)（V-ed）+宾语. He hasnt finished it. They have worked it out.一般疑问句：Have/Has+主语+动词的过去分词(p.p)（V-ed）+宾语.Has he finished it? Yes, he has; No he hasntHave they have worked it out? Yes, I have; No I havent 特殊疑问句：特殊疑问词或词组+have/has+主语+过去分词（v-ed）
