certain的形容词是certainly；副词形式为certainly。certain作形容词时，意为“某一；必然的；确信”；作代词时，意为“某些；某几个”；作名词时，意为“人名；(葡)塞尔塔因；(法)塞尔坦”。例句：Or only certain people had them?亦或只是某些人拥有它们？I have certain reservations about it.对此我有某些保留意见。

certain：英[ˈsɜːtn]；美[ˈsɜːrtn]

pron.(不提及人或事物的名称时用)某些

adj.肯定；确定；确实；确信；无疑；(不提及细节时用)某事，某人，某种；某某，某位，一位叫…的；轻微的

比较级：more certain

最高级：most certain

certain event.[数]必然事件；肯定变乱

Almost certain.十拿九稳；几乎肯定；肯定发生；几乎可以肯定的

certain areas'.某些地区；定煊；某些领域；若干地区

certain plants.某些植物

certain about.有把握；确信；确实

certain regulations.的若干规定；某些规例；若干规定

Certain medications.某些药物

Netma certain.网络人

1、Certain of those present were unwilling to discuss the matter further.

某些在场的人不愿意进一步讨论这个问题。

2、Those beliefs still prevail among certain social groups.

这些信念在某些社会群体中仍很盛行。

3、The work must be completed within a certain time limit.

这项工作必须在一定期限内完成。

4、The company's financial position is not certain.

这家公司的财务状况不明朗。

5、Many animals breed only at certain times of the year.

很多动物只在一年的某个时候交配繁殖。

6、To my certain knowledge he was somewhere else at the time.

我敢肯定他当时在别处。

7、I'm not certain who was there.

我无法确定谁当时在场。

8、As things stand at present,he seems certain to win.

据目前情况看，他似乎胜券在握。

9、I can't say for certain when we'll arrive.

我说不准我们什么时候能到。

10、It can be seen that certain groups are more at risk than others.

看得出，有的组风险大，有的组风险小。

11、You'll have to leave soon to make certain of getting there on time.

你得快点出发，好确保准时到达那里。

12、For certain personal reasons I shall not be able to attend.

由于某种个人原因，我将不能出席。

13、I accept his theories,but not without certain qualifications.

我接受他的理论，但并非毫无保留。

14、A certain person told me about it.

有人告诉了我这件事。

15、I'm fairly certain I can do the job.

我有相当把握能干这项工作。