certain
Definitions
Completely sure; having no doubt that something is true or will happen.
确定的；确信的；毫无疑问的。
Sure to happen; inevitable.
必然的；一定会发生的。
Used to refer to a particular but unspecified person or thing.
某一（不点名的）；某些。
Root Breakdown
Root-derivedStraight from Latin certus ('settled, sure'), the past participle of cernere ('to sift, decide'). Something certain has, in effect, been sifted clean of doubt — sorted and settled. The 'a certain person' sense bends the same 'fixed/decided' idea toward 'definite but unnamed.'
Root cert still carries 11 more wordsWhy It Means This
Behind 'sure' lies a farming image: certus is what cernere ('to sift') leaves behind. Sift a matter long enough and the doubt falls away like chaff; what remains is certain. That is why the word feels final — not just 'I think so' but 'it has been settled.'
Common Collocations
- 1.be certain of确信……
- 2.make certain确保
- 3.for certain确切地
- 4.a certain amount of一定数量的
- 5.certain conditions某些条件
Example Sentences
- 1.
I'm certain I locked the door before we left.
- 2.
One thing is certain: prices will keep rising.
- 3.
A certain Mr. Lee called while you were out.
- 4.
Under certain conditions, the deal could still fall through.
Easily Confused
certain vs sure — In everyday speech they overlap (I'm sure / I'm certain), but certain is slightly more formal and emphatic, and works better with impersonal subjects: 'It is certain that...' sounds right; 'It is sure that...' does not. Use sure for personal feeling, certain for objective settledness.
Synonym Comparison
- certain — settled beyond doubt; works with impersonal 'it is certain that'
- sure — personal confidence; more casual
- positive — emphatic, often spoken: 'I'm positive I saw him'
- confident — feeling of self-assurance, not necessarily about facts
- definite — fixed and clearly defined, often about plans: a definite answer