certain

• 表示某事是已知为真、确定或具体的，但未详细说明或命名；也可表示对某事有把握。

Used to indicate that something is known to be true, definite, or specific, but not named or described in detail.

1. Sure or confidentA2formal

   Having no doubt; completely sure about something.

   确定的

   • I am certain that she will arrive on time.
   • He is certain of his decision.
   • Are you certain about the directions?

   同义词assuredconfidentconvinceddoubtlesspositivesureunhesitatingunwavering

   反义词doubtfuluncertainunsurewavering

2. Specific but not namedB1formal

   Used to refer to a particular person, thing, or group without naming them explicitly.

   某个

   • A certain person called while you were out.
   • There are certain rules you must follow.
   • She has a certain charm that attracts people.

   同义词oneparticularsomespecificunnamedunspecified

3. Inevitable or definiteB1formal

   Something that is bound to happen; unavoidable.

   必然的或确定的

   • Change is certain in life.
   • It is certain that the project will be completed by Friday.
   • The outcome of the election is not yet certain.

   同义词assuredbounddefinitedestinedfatedinescapableinevitableinexorablesureunavoidable

   反义词doubtfulquestionableuncertainunlikely