1、I've never heard of anyone doing that.我从未听说有人做那种事.
2、l have played the piano .我已经弹过钢琴了.
3、It is the most beautiful view I have ever seen.这是我至今见过最美的风景
4、He has taught here since 1981 .他自1981年就在这儿教书.（可能还要继续教）
5、I have't seen her for four years.我有四年没见到她了.
6、I have been to Beijing twice.我去过北京二次.
7、We have already finished our homework.我们已完成作业了.
8、They haven't finished their homework yet.他们还没有完成作业.
9、Have you ever been to the Great Wall?你曾经去过长城吗?
10、I have been here for half an hour. 我已经在这里半小时了。
11、现在完成时表示 过去发生的动作对 现在造成的 影响或 结果或表示过去的动作或状态 持续到现在。 它的构成是：主语+have/has +动词的过去分词。