If you are certain about something, you firmly believe it is true and have no doubt about it. If you are not certain about something, you do not have definite knowledge about it.
sure
uncertain
She's absolutely certain she's going to make it in the world.
她深信自己将享誉全球。
We are not certain whether the appendix had already burst or not.
我们不能确定阑尾破了没有。
If you say that something is certain to happen, you mean that it will definitely happen.
However, the scheme is certain to meet opposition from fishermen's leaders.
不过这个计划肯定会遭到渔夫头领们的反对。
It's not certain they'll accept that candidate if he wins.
如果那位候选人胜出,无法肯定他们是否会接受他。
The prime minister is heading for certain defeat if he forces a vote.
如果首相强令大家投票表决,那他一定会遭遇失败。
If you say that something is certain, you firmly believe that it is true, or have definite knowledge about it.
One thing is certain, both have the utmost respect for each other.
有一点是确定无疑的,即两人对彼此都极其敬重。
It is certain that stammering becomes more pronounced when the rate of speech is increased.
可以确定的是:当说话频率加快时,口吃变得更明显。
You use certain to indicate that you are referring to one particular thing, person, or group, although you are not saying exactly which it is.
There will be certain people who'll say 'I told you so!'
会有某些人说,“我告诉过你了!”
This can create a marked improvement in certain skin conditions.
这可以使某些皮肤问题得到明显的改善。
Leaflets have been air dropped telling people to leave certain areas.
传单被空投下来,告诉人们离开某些区域。
You owe a certain person a sum of money.
你欠着某人一笔钱。
You use a certain to indicate that something such as a quality or condition exists, and often to suggest that it is not great in amount or degree.
That was the very reason why he felt a certain bitterness.
那正是他感到有点痛苦的原因。
for certain
If you know something for certain, you have no doubt at all about it.
She couldn't know what time he'd go, or even for certain that he'd go at all.
她不知道他何时要走,甚至于还不能确定他究竟要不要走。
make certain
If you make certain that something is the way you want or expect it to be, you take action to ensure that it is.
Parents should make certain that the children spend enough time doing homework.
父母应该确保孩子花足够多的时间做作业。
When you refer to certain of a group of people or things, you are referring to some particular members of that group.
They'll have to give up completely on certain of their studies.
他们将不得不完全放弃某些课程。