ought/should与进行式连用时表示主语没有履行其义务，做了愚蠢、鲁莽的事等或做事不明智、不慎重等：

　　He ought to be studying for his exam.He shouldn't be spending all his time on the beach.

　　他本该正在学习以备考试。他不该把他的全部时间都在海滩上度过。We should be wearing seat belts.

　　我们应该系好安全带。(但我们没有系安全带。)

　　I shouldn't be telling you this.It's supposed to be a secret.

　　我不应该告诉你这件事。这是个秘密。