现在完成时专题1.用法：过去发生的动作对现在造成的影响或结果，强调结果。标志性的词语有just, already, before, yet, never, ever,recently（最近），. 例：I have finished my homework already.过去已经开始一直持续到现在的动作或状态。标志性的词语for、since ，so far（句中谓语动词要用延续性动词）例：I have lived here since 1990.2.现在完成时的构成 主语+havehas+过去分词+其它3.现在完成时的四个基本句型一般疑问句： Has he finished the work?两回答： Yes ,he has. No, he hasnt. 肯定句： He has finished the work. 否定句： He has not finished the work. 特殊疑问句： What has he done？ 4.在下列情形下
