Translation guide
This guide covers how to express that something is guaranteed, certain, or assured in Japanese. It focuses on natural expressions for promises, certainty, and conditions, rather than direct translations of the English word.
The quality is guaranteed.
We guarantee a refund.
Means 'comes with a guarantee'. Used for products or services that include a warranty.
This product comes with a one-year guarantee.
A somewhat old-fashioned or literary verb meaning 'to guarantee' or 'to assure'. Not common in everyday speech.
Success is guaranteed.
Expressing that something is inevitable or bound to happen, without implying a person's promise.
Means 'must be' or 'no doubt'. Used when you are very sure about something based on evidence or intuition.
He's guaranteed to come. / He must be coming.
This plan is guaranteed to succeed.
Indicates a strong expectation based on reason or logic. 'It should be that...'
He's guaranteed to know. / He should know.
Adverb meaning 'without fail', 'definitely'. Can be used to emphasize certainty.
It's guaranteed to rain.
Adverb meaning 'always', 'without exception'. Used for things that are certain to happen.
Expressing that one thing is guaranteed if another condition is met, often in rules or logic.
The English word 'guaranteed' is often used loosely (e.g., 'It's guaranteed to be fun!'). In Japanese, 保証する (hoshō suru) is more formal and implies a concrete promise or warranty. For casual certainty, use patterns like 〜に違いない or 必ず instead.
努力すれば必ず報われる。
If you work hard, success is guaranteed.