肯定他會同意[他一定同意].

對那事我完全可以肯定。

任何替代肯定會稍遜一籌的。

確定事物正確性的一種檢查。

sure和certain的用法常常是相同的

【記】※ curtain-窗簾,certain-確定的:窗簾安在確定的位置上 ※ ce-拼音“廁”,r-似“花”,tain-拼音“太難”:廁所里養花確實太難了 ※ c-似“月亮”,er-拼音“兒”,ta-拼音“塔”,in-在…里:月兒在塔里是一定的

certain adj 1 [pred 作表語] ~ (that...); ~ (to do sth) sure beyond doubt; that can be relied on 無疑; 確定 It is certain that he will agree/He is certain to agree. 肯定他會同意[他一定同意]. One thing is certain: I'm not coming here again. 有一件事可以肯定, 我再也不來了. 2 [pred 作表語] ~ (that...); ~ (of/about sth) positive in one's mind; completely sure 確信; 肯定 I'm certain (that) she saw me. 我肯定她看見我了. She saw me: I'm certain of that. 她看見我了, 這一點我可以肯定. I'm not certain (of) what she wants. 我不清楚她想要什麼. 3 [attrib 作定語] sure to come, happen or be effective; assured 一定會來到、 發生或生效的; 有把握的 There is no certain cure for this disease. 這種病沒有特效藥. They face certain death unless they can be rescued today. 他們除非今天獲救, 否則必死無疑. 4 [attrib 作定語] specific but not named or stated 某（不指明的或不說出的） For certain reasons I will be unable to attend the meeting. 因為某種原因, 我不能出席這次會議. The terrorists will only release their hostages on certain conditions. 恐怖分子只有在某些條件下才釋放人質. 5 [attrib 作定語] named but not known 說出姓名但不認識的 A certain Mr Brown telephoned while you were out. 你出去的時候, 有個叫布朗的先生來過電話. 6 [attrib 作定語] slight; some 稍微的; 一些的; 一點兒的 There was a certain coldness in her attitude towards me. 她對我的態度有點兒冷淡. I felt a certain reluctance to tell her the news. 我不太愿意告訴她這個消息. 7 (idm 習語) for `certain without doubt 無疑地; 確定地 I couldn't say for certain when he'll arrive. 我說不準他什麼時候到. I don't yet know for certain. 我知道得不確切. make certain (that...) inquire in order to be sure about sth 弄清楚; 弄明白; 弄確實 I think there's a train at 8.20 but you ought to make certain. 我想8點20分有一班火車, 不過你應該打聽清楚. make certain of sth/of doing sth do sth in order to be sure of (doing) sth else 采取行動以便確有把握做其他事 You'd better leave now if you want to make certain of getting there on time. 你要想準時到達那里就最好馬上走. certain, pron ~ of... some particular members of (a group of people or things) （人或物中的）某些 Certain of those present had had too much to drink. 有些出席的人喝得太多了. certain, NOTE ON USAGE 用法 Sure and certain are often used in the same way *sure和certain的用法常常是相同的 They're sure/certain to be late. 他們一定遲到. I'm sure/certain (that) they'll be late. 我肯定他們得遲到. One thing was sure/certain they'd be late. 有一件事是確定無疑的, 他們得遲到. They made sure/certain (that) they weren't late. 他們有把握不遲到. With `it' as an indefinite subject or object only certain can be used *it作不定主語或不定賓語時, 只可用certain與之連用 It was certain/ I thought it certain that they would be late. 肯定[我肯定]他們要遲到. Sure can sound weaker than certain, especially in conversation *sure的語氣聽起來比certain弱些, 特別是在對話中 I'm sure he'll manage it, ie I think/hope he will. 我確信他能辦到（即我認為[希望]他能辦到）.

*['s?:t?n]a. 確定的, 某一個的, 必然的【法】 確鑿的, 無疑的, 可靠的相關詞組: be certain of It is certain that I am certain that... I am not certain whether... to a certain extent for certain