adj(1)肯定(无疑)的，一定的(always true;without doubt)[作pred][A+that，A+to-inf]：It is～that he will succeed/he won the election. 他肯定会成功/在选举中获胜了。It is～that the world is round.地球肯定是圆的。That we should stay together/the diamonds were real was～.肯定无疑，我们应该一起留下来/钻石是真的。Whether he will do it is not～.他不一定干。One thing is～： he is right . 有一点是肯定无疑的：他没错。He is (pretty)～to succeed/to return/to forget.(很)肯定他会成功/会回来/会忘记。The duties are～to be heavy.这些职责一定很重。The strikes are～to have been given careful consideration.这些罢工一定经过了精心的策划。It is～to produce a strong impression. 这肯定会产生强烈影响。〖同〗sure，definite，positive;〖反〗unsure，indefinite，doubtful，unlikely;

(2)确信的，有把握的(positive in one's mind;absolutely sure)[作pred][A+that，A+wh，A+wh-inf，A(of/about)]：He is (quite/perfectly)～that she will succeed/I will get over my illness/they saw us. 他(很/完全)有把握她会成功/我会痊愈/他们看见我们了。Are you～that you'll come/you left the book here? 你肯定会来/是把书落在这儿了吗? Be～you arrive on time.你一定要准时到达。You may be～I will hurry.你可以放心我会抓紧的。He is not～whether she will come/who the man is/what to do.他不能肯定她是否会来/那人是谁/该怎么办。He is～of her success/the future/what they said.他对她的成功/未来/他们说的话确信不疑。He is～about her qualifications for the post/her ability to handle the job.他确信她担任这个职务是称职的/她有能力处理这项工作。I'm not quite～of(about) it.我对此把握不大。Are you～of what you say? 你对你说的情况确信无疑吗? 〖同〗sure，positive，confident;〖反〗uncertain，doubtful;

(3)肯定的，无疑的(sure beyond all doubt or question;inevitable)[作attrib]：Being constantly late is a～way of losing one's job.经常迟到无疑会丢掉工作。The new medicine is an almost～remedy for this disease.这种新药对医治该病有可靠的疗效。It's a～cure for the disease/the illness/a headache.这肯定能治这种病/这种病/头痛。face～death/defeat必死/败无疑;Capture means～death.抓住就得死。〖同〗definite，inevitable;〖反〗indefinite，unlikely，doubtful;

(4)某些，不确定的(specific but not definitely named or described)[作attrib]：～members of Parliament/government某些国会议员/政府官员;for～reasons由于某些原因;on～conditions在某些条件下;There were～laws for automobile safety.关于汽车安全有一些法律规定。There were～differences constantly cropping up.总是不断出现一些分歧。〖同〗specific，particular;

(5)某(个)(named but not well-known)[作attrib]：A～Mr Jackson telephoned you just now.刚才有个叫杰克逊的先生给你打电话来。A～person has been asking questions about you.有个人一直在询问你的情况。〖同〗 specific，particular，individual;

(6)有点(些)(some(but not much))[作attrib]：to a～degree/extent到某种程度/范围;There is a～hostility in his manner/coldness in his attitude/amount of improvement in his health.他的态度有点敌意/态度有点冷淡/健康状况有所好转。have a～amount of admiration for sb对某人有些钦佩;a～share of the profits一份利润;make a～profit/concession获得一些利润/做出一些让步;feel a～reluctance/coldness觉得有点不情愿/冷漠;rouse a～enthusiasm激起一定的热情;〖同〗specific，particular;

for certain肯定(无疑)地，有把握地：I know (don't know/can't say) for～that he is lying/what will happen. 我肯定(不肯定/不能肯定)他是在撒谎/会发生什么事。I shall be there/It will happen for～. 我肯定在那儿/这肯定会发生。

make certain that 弄(搞，问)清楚(确实)：You'd better make～(that)he doesn't have any weapon on him/this is the right number你最好搞清楚他身上确实没带武器/这个号码确实没错。Please make sure(that) he'll be there.请搞清楚他确实会去那儿。I think he is dead， but you'd better make～. 我想他是死了，但你最好确认一下。

make certain of 确保：He hurried off to the theatre to make～of getting a good seat.他匆忙赶往剧院以确保占个好位子。No one can make～of living till one hundred.没有一个人能确保自己活到100岁。Always make～of your facts.永远要保证事实准确无误。

→′certainty n 肯定(必然)的事;必然，确实;un′certain adj 不确定(知)的;′certainly adv;

pron 某(有)些(some but not all(of))[接of]：C～of the things he said were downright lies.他说的事有些是彻头彻尾的谎话。C～of the people complained more loudly than others.有些人抱怨得比别人更厉害。

【说明】 He is certain to succeed. It is certain that he will succeed.是说话者肯定地认为主语(he)一定能成功。(见第(1)义)。He is certain of succeeding/his success.意思不完全相同，是指主语(he)自己的精神状态(自己确信自己肯定能成功，但不一定正确)(见第(2)义)。

【辨异】 certain与sure语义相近，用法亦差不多，常可互换，如：都可用于be～to do sth，be～that ...，make～that等结构;但是有差别。用法上，在 It is～that 和think it～that 结构中，只可用certain，不可用sure;语义上，当确知真相、有肯定的理由消除怀疑时用certain，仅仅是不怀疑时用sure，如：I'm certain he didn't steal it. I stole it myself.(我肯定他没有偷。是我自己偷的。)I'm sure he didn't steal it. He's not that kind of person.(我确信他没有偷。他不是那种人。)这种语义上的区别也反应在certainly和surely上。还有confident(确信的)表示强烈的信念，如：I'm confident that I will succeed.(我确信我会成功。)positive(确信的)表示强烈的信念，甚至是过分地自信，有点武断，如：I'm positive that he is mad.(我敢断定他是疯了。)