Usage patterns 〈 事こと 〉 は 確かく 実じつ だ it is certain that ~
His election victory is certain.
確かく 実じつ に 〈 動どう 詞し 〉 to surely/reliably do something
This medicine reliably works.
〈 物もの 〉 を 確かく 実じつ にする to make something certain/secure
I'll book early to secure my seat.
確かく 実じつ な 〈 物もの 〉 a reliable/certain (method, information, etc.)
I want to earn money through a reliable method.
Related words· 6 確か is more subjective, often meaning 'I believe' or 'if I recall correctly', while 確実 expresses objective, evidence-based certainty.
明確 emphasizes clarity and lack of ambiguity, while 確実 emphasizes reliability and the absence of doubt about an outcome.
間違いない is a casual, conversational way to say 'no mistake about it', while 確実 is the more formal, written-register word for certainty.
確実 is a formal adjective meaning 'certain/reliable', while 鉄板 is a casual noun used for something guaranteed to succeed.
Show 2 more Show fewer 確実 is the standard modern word for 'certain, reliable' and can stand alone freely, whereas 確 cannot be used independently outside set expressions.
確実 stresses certainty that something will happen as expected, whereas 手堅い stresses avoiding failure through careful, low-risk choices.
Opposites 不確実 simply negates 確実 , describing something uncertain or unreliable rather than firmly established.
確実 means 'certain, sure' in a more formal or objective sense, contrasting with 不確か 's lack of certainty.
Don't confuse with 確信 is a noun meaning a person's firm personal conviction, whereas 確実 describes the objective certainty of a fact or outcome.
確認 is a verb-forming noun meaning 'to confirm/check', while 確実 is an adjective describing something as already certain, not an act of checking.
確固 describes an unwavering attitude or belief, while 確実 describes the certainty or reliability of a fact, plan, or outcome.
確実 means 'certain, sure to happen,' while 着実 means 'steady, gradual progress'; the two share the kanji 実 and similar sound but differ in meaning.
Word family regard as certain; see as a sure thing
uncertain; unreliable; inauthentic; insecure
degree of certainty; certainty
certainty; reliability
projected to win; certain to be elected
Etymology Compound of 確 (certain, firm) and 実 (truth, reality). The combination conveys the idea of something being solidly true or dependable.
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