关于前面讨论的“it is +形容词+ of sb to do sth”句式，我也有一个问题，那就是其中的不定式可以用完成式吗？比较：
It was kind of them to help me.
It was kind of them to have helped me.
It was nice of you to come.
It was nice of you to have come.
It was stupid of you to leave the door unlocked.
It was stupid of you to have left the door unlocked.
可以。网友说的两种表达都对！
因为It is + adj. + of sb. to do sth. 结构，是 Sb. is + adj. + to do sth. 的变式，所以，大家完全可以用不定式的“完成体”，表示不定式的动作业已完成，而且早于be 动词：It is + adj. + of sb. to have done sth.这也是不同于It is + adj. + for sb. to do sth. 结构的一个要紧标志。
比如：
Its too kind of you to have told me that.
你把那件事告诉了我，真是太好了。
来自《简明英汉词典》
It was really very kind of you to have done so much washing for me.
帮我洗了这么多衣服,难为你了!
来自《现代汉英综合大词典》
It is too kind of you to have reminded me of that.
你准时提醒我那件事,真是太好了。
Its very kind of you to have given us much help.
你给了大家那样多的帮忙真是太好了。
Its very kind of you to have invited me.
很感谢你的盛情邀请。
Its very kind of you to have listened to me.
你听了我的话真好。
Its very kind of you to have accompanied me here tonight.
谢谢你今晚陪我。
