sure与certain sure和certain两个形容词都表示“确信，有把握”，两个词在大多数情况下可以互换使用，但使用中是有细微差别。 1.sure的意思是“确信的”，它是一个普通用词，仅仅暗指无疑，不踌躇。多指主管感觉。比如： Are you sure you should be up?你肯定你该起床了吗?I'm sure we'll manage without.我相信我们能凑合的。I'm pretty I'll be going.我肯定会去的。I hope you are sure of your facts.我希望你能肯定你说的都是事实。Are you sure about that?这事你肯定吗？ 2.certain的意思是“确信的，有把握的”，指基于特别的根据或者证据而确信，比sure语气更强。比如： It is certain that they will agree/They are certain to agree.他们肯定会同意。She wasn't certain (that) he had seen her.她不敢肯定他见过她。 Are you certain about this?你对这事确信无疑吗？I'm not certain who was there.我无法确定谁当时在场。 It is certain that they will agree/They are certain to agree.他们肯定会同意。The climbers face certain death if the rescue today is unsuccessful.救援行动如果今天不能成功，登山队员必死无疑。