词典解释
certain 英[ˈsɜ:tn] 美[ˈsɜ:rtn]
adj. 某一; 必然的; 已确定的;
pron. [动词用复数] 某些;
比较级：more certain 最高级：most certain
certain的用法详解
You see, I…I am crazy. I take the newer medications, but I still see things that are not here. I just choose not to acknowledge them. Like a diet of the mind, I choose not to indulge certain appetites. Like my appetite for patterns. Perhaps my appetite to imagine and to dream.
——A Beautiful Mind
你要明白，我……我是疯的。我服用最新的药物，但我仍然看的见那些不存在的东西。我只是选择了不去理睬他们。就好像一顿心灵快餐，我选择不去纵容某些食欲。比如说我症状的食欲。还有我虚构和想象的食欲。
——《美丽心灵》
1. be certain of [about] sth 对某事有把握或感到自信。如：
He’s certain of success. 他自信会成功。
Are you certain of [about] that？ 你对此有把握吗？
2. be certain to do sth 肯定会发生某事。如：
She’s certain to pass the exam. 她考试肯定会及格。
Spring is certain to follow winter. 冬季过后一定是春天。
注：该结构有时可用 I am certain that 来转换。如：
He is certain to come. / I am certain that he will come. 他肯定会来。
3. be certain of doing sth 确信会发生某事。如：
He is certain of winning the match. 他确信能赢这场比赛。
注：该结构有时可与后接 that 从句的句型转换。如：
He is certain of passing the exam. / He is certain that hecan pass the exam. 她确信考试会及格。
4. for certain 有把握，肯定地。如：
I don’t know for certain. 我知道得不确切。
I can’t say for certain when he will come. 我不敢肯定地说他什么时候来。
5. make certain 弄清楚，弄得有把握，核实。如：
(1) 单独使用。如：
I think the train leaves at six o’clock but you ought to make certain. 我想火车是六点开吧，但你应该查清楚。
(2) 后接 that 从句。如：
Make certain (that) you know what time the train leaves. 你要弄清楚火车开出的确切时间。
(3) 后接 of 短语。如：
You must make certain of the date of the meeting. 你必须把开会的日期弄清楚。
We went to the theatre early and made certain of getting seats. 我们去戏院很早，以便可弄到座位。
注：有时以上各结构可互相转换。如：
Make certain of his safe arrival. / Make certain that he arrived safe. 弄清楚他是否安全抵达了。
