完成式表示的動作或狀態(tài)發(fā)生在謂語動詞表示的動作或狀態(tài)之前。下面舉例說明一下。

　　如：

　　I am sorry to have kept you waiting. (=I am sorry that I have kept you waiting)

　　對不起，讓你久等了。

　　注意：

　　若謂語表示“愿望、打算、意圖”的動詞時。

　　如hope，think，want，plan，expect，mean，

　　intend等，其后可以跟不定式的完成式表示“本來想要或打算做某事，而實際上未能實現(xiàn)”。

　　如：

　　We meant to have stopped him from doing such a thing.

　　不定式完成式的用法

　　1、表示發(fā)生在謂語動作之前的動作：

　　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 believe it to have been a mistake.

　　我相信這是一個錯誤。

　　You appear to have travelled quite a lot.

　　你似乎作過多次旅行。

　　I’m sorry to have given you so much trouble.

　　對不起給了你這么多麻煩。

　　It’s said to have been built in the Ming dynasty.

　　據(jù)說它是明朝修建的。

　　2、表示在某個給定的時間之前已完成的動作：

　　I hope to have finished the work by now.

　　我希望現(xiàn)在以前已完成這項工作。

　　3、表示過去未曾實現(xiàn)的想法和愿望：

　　I should like to have come earlier.

　　我本想早點來的。

　　We were to have been married last year.

　　我們本來打算去年結婚的。