這個結構用來表示沒有覆行義務或不明智地忽略了該做的事。在否定式中這一結構表示從前發生的、錯誤的或愚蠢的事。

　　You ought to have told him that the paint on that seat was wet.

　　你本應該告訴他椅子上的油漆還沒有干。

　　You should have turned his omelette;he likes it turned.

　　你本應該給他攤的雞蛋翻個身的;他喜歡吃兩面都煎透的攤雞蛋。

　　They ought to have stopped at the traffic lights.

　　他們本應在紅綠燈處停下。

　　She shouldnt have opened the letter;it wasnt addressed to her.

　　她不應該拆開信，信封上寫的不是她的名字。

　　The Emergency Exit doors shouldnt have been blocked.

　　緊急出口的門本來不應被堵死。