for certain
Speech parts
1. for certain - Adverb
2. for certain - Phrase
Meaning
definitely or positively (`sure' is sometimes used informally for `surely')
Source: WordNetSynonyms
Antonyms
Examples
War is smaller in scale than in recent memory, but it is far more ambiguous, intractable, and nasty. Money flows more quickly than ever, but it is still somehow manages to gather and puddle in certain places, for certain people rather then others.
So true is it that all transactions of preeminent importance are wrapt in doubt and obscurity; while some hold for certain facts the most precarious hearsays, others turn facts into falsehood; and both are exaggerated by posterity.
We should see the leadership from the White House setting dates certain for certain goals of achieving greater alliance on alternative and renewable energy sources, but we are not.
Everything happens for a reason, and part of that beauty of life is that we're not allowed to know those reasons for certain.
All I know for certain is that reading is of the most intense importance to me; if I were not able to read, to revisit old favorites and experiment with names new to me, I would be starved - probably too starved to go on writing myself.
Of your wife and your tried friend believe nothing but what you know for certain.