確 実(かくじつ)

かくじつ

na-adjective, noun

certain, reliable

1. certain, sure, definite

Something that is beyond doubt; guaranteed to happen.

成功(せいこう)は確実(かくじつ)だ。

Success is certain.

合格(ごうかく)は確実(かくじつ)ではない。

Passing is not certain.

この天気(てんき)なら、明日(あした)の試合(しあい)は確実(かくじつ)に行(おこな)われるだろう。

With this weather, tomorrow's game will certainly take place.

2. reliable, sound, steady

Trustworthy and dependable; not likely to fail.

確実(かくじつ)に届(とど)く方法(ほうほう)を教(おし)えてください。

Please tell me a method that will reliably deliver it.

確実(かくじつ)な情報(じょうほう)がほしい。

I want reliable information.

確実(かくじつ)に届(とど)けるために、書留(かきとめ)で送(おく)った。

I sent it by registered mail to ensure reliable delivery.

確実(かくじつ) means certain, reliable, or definite. It can function as both a na-adjective and a noun.

Forms

Na-adjective: 確実(かくじつ)な (certain, reliable)
Adverbial: 確実(かくじつ)に (certainly, reliably)

Common patterns

確実(かくじつ)に〜する (to do ~ reliably/for certain)
確実(かくじつ)な方法(ほうほう) (reliable method)
確実(かくじつ)な証拠(しょうこ) (definite evidence)
確実(かくじつ)性(せい) (certainty, reliability)

Similar words

確(たし)か: 'probably,' 'if I remember correctly' - expresses uncertainty
確実(かくじつ): 'certain,' 'definite' - expresses certainty
間違(まちが)いない: 'no doubt,' 'definitely'

Related Words

Compare: 確(たし)か (probably)

Antonym: 不確実(ふかくじつ) (uncertain)

Compare: 間違(まちが)いない ('no doubt,' 'definitely')

Related: 確(たし)かめる (to confirm, to verify)

Compare: 着々(ちゃくちゃく) (steadily)

Related: 着実(ちゃくじつ) (steady)

Compare: 着実(ちゃくじつ)に (steadily, surely)

Compare: 確定的(かくていてき) (definite)

general

Added 2026.1.11 18:17 · Revised 2026.9.4 21:29

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