NHK : 名詞形式...就是後面加 ty = Certainty~...而加 ly...就是副詞 = Certainly~.........

certain

['sə:tən]

adj. 某一；必然的；確信；無疑的；有把握的

pron. 某些；某幾個

同義詞

a. sealed，sure

反義詞

a. incertain，uncertain，unsealed，unsure

參考例子

1.Stress prompts the body to produce certain stress hormones.

壓力促使身體產生一定的壓力荷爾蒙。

2.In certain areas of North China there was also the risk of attack by bandits who preyed on unsuspecting travelers.

在中國那裡北部的某區域中也是藉著在無懷疑的旅客身上捕食的強盜攻擊的危險。

3.As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality.

就數學規律能涉及現實生活中而言，他們是不確定的，就他們的確定性來說，他們就不能涉及到現實生活中。

英文解釋

adj.

1.definite but not specified or identified

2.having or feeling no doubt or uncertainty; confident and assured

3.established beyond doubt or question; definitely known

4.certain to occur; destined or inevitable

5.established irrevocably

6.reliable in operation or effect

7.exercising or taking care great enough to bring assurance

網路釋義

Certain

某，某些，確定的，一定的; 確定的; 確鑿的; 確實;

make certain

(把…)弄確實，弄清楚; 確信; 弄確實，查明; 弄清楚;

a certain

某一; 某一個(接可數名詞單數); 一定的; 一定;

certain areas

某些地區; 某些地;

certain knowledge

準確的知識; 正確的知識