1、定义：1.过去发生的动作对现在有影响例如:She has cut her hair.2.动作从过去延续到现在，可能还要持续下去例如：He has worked here for5 months.
2、标志词：already（肯定）yet（否定/ 疑问）just, before, recently, still, lately, ne即枢潋雳ver, ever, never, twiceon several occasionin the past/ last few days/ weeks/ months/ years(up to) these few days/ weeks/ months/ yearsthis morning/ week/ month/ yearup to present/ nowso fartill nowsince + 时间
3、肯定句：He/she/it+ha衡痕贤伎s+过去分词You/We/They+have+过去分词否定句：He/she/it+hasn't+夸臾蓠鬏过去分词You/We/They+haven't+过去分词疑问句：Have/has+主语+过去分词？
4、最后，牢记时态的方法就是多做题