GrammarN12 min read2026-02-17

〜ずにはすまない/ないではすまない

Express an obligation driven by duty, social norms, or the circumstances around you.

Meaning

This grammar pattern expresses something that must be done, considering one's sense of duty, the surrounding circumstances, or common social expectations. It conveys the idea that failing to act would be unacceptable or inexcusable.

Formation

Part of speechFormation
Verb (ない-form)ずにはすまない/ないではすまない
する (Group 3 verb)せずにはすまない/しないではすまない

Examples

  1. あれだけみんなに迷惑をかけておいて、知らないではすまない。
    After causing that much trouble for everyone, you cannot just pretend you do not know about it.

  2. お宅の子はこんな高価な芸術品を壊したのだから、弁償しないではすまないよ。
    Your child broke such an expensive piece of art, so you cannot get away without paying for it.

  3. お客様から仕事を受けた以上、今更できないではすまない。
    Now that we have accepted the job from the client, we cannot just say we cannot do it at this point.

  4. 4年かけてやっとここまで来たんだ、最後までやり遂げずにはすまない。
    It took four years to get this far; I absolutely must see it through to the end.

Summary

  • 「〜ずにはすまない/ないではすまない」means "must; cannot get away without"
  • Attaches to verbs (ない-form); する becomes せずにはすまない
  • It is often used with verbs such as 「謝る」(to apologize), 「弁償する」(to compensate), 「責任を取る」(to take responsibility), and 「返す」(to return).

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