不定式的完成式概念：

不定式的完成式主要表示已经完成的动作—既可能是表示先于谓语动作已经完成，也可能是先于某个特定时间已经完成。
如：I am sorry to have kept you waiting. (=I am sorry that I have kept you waiting) 对不起，让你久等了。

不定式的完成式（to have+过去分词）的用法：

1、表示在主句谓语的动作之前发生的事情：
如：I'm glad to have met your parents here. 我很高兴在这儿见到了你父母（已见过）
        I'm sorry to have kept him waiting for me so long. 我很抱歉让他等了我这样久。（已经等过了）
2、动词不定式的完成式和下列动词的过去时连用，表示过去没有实现的事情：plan, hope, expect, be, intend, mean,w ish,等。注意一定是它们的过去时。另外还有should/wouldlike/love。这个结构表示“本打算/想/计划…”的意思。
例如：The game were to have taken place in Room. 比赛原计划在罗马举行。
            He planned to have gone abroad last week.=He planned to go abroad but he didn't. 他原计划上周出国的。
            I'd like to have been offered the job and(to have been)given the opportunity to prove myself. 我真想（当时）把这个工作给了我，给我个机会让我证明我自己。
同样的意思也可用上述动词的过去完成时加动词不定式的一般式来表达。
例如：I had hoped to visit the great pyramid.
          =I hoped to have visited the great pyramid.
          =I hoped to visitit, but I didn't. 我本希望参观大金字塔的。
            They would have liked to have your help.
          =They would like to have had your help.
          =They wanted to have your help but they didn't have it. 他们本想得到你帮助的。

动词不定式时态知识体系：

不定式完成式的三点用法说明：　

（1）表示发生在谓语动作之前的动作。
如：He seems to have caught a cold. 他似乎感冒了。 　　
        I hate to have quarreled with her. 我后悔和她吵架了。 　　
        I'm sorry to have given you so much trouble. 对不起给了你这么多麻烦。 　　
（2）表示在某个给定的时间之前已完成的动作。
如：I hope to have finished the work by now. 我希望现在以前已完成这项工作。 　　
（3）表示过去未曾实现的想法和愿望。
如：I should like to have come earlier. 我本想早点来的。 　　
        We were to have been married last year. 我们本来打算去年结婚的。