certain/ˈsɜːt(ə)n/
adj.1. 确实的；无疑的The evidence is certain and the facts are clear.证据确凿，事实清楚。
I am certain he told me to come at two o'clock.我肯定他告诉我两点来。
There's no certain cure for this illness at present.现在这种病尚无确实可靠的疗法。
2. 一定的；确信的；必然的I'm certain she saw me.我确信她看到我了。
We are certain of victory.我们一定会获得胜利。
Are you certain that you'll get there in time?你有把握及时赶到那里吗？
The right party are certain to be victorious.正义的一方一定会胜利。
She's certain to do well in the examination.这次考试她肯定考得好。