modality N1 uncommon written
〜ずにはすまない — can't get away without ~ing
〜ずにはすまない ・ ずにはすまない
Builds on ない形
Meaning
- one cannot get away without ~ing / will inevitably have to ~ — social or moral pressure makes the action unavoidable
Key sentence
壊してしまった以上、弁償せずにはすまない。
Now that I've broken it, I can't get out of paying for it.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Verb ない-form (drop ない) + ずにはすまない（する → せずにはすまない） | Vない(→ず) + にはすまない |
Examples
これだけ迷惑をかけたら、謝らずにはすまないだろう。
After causing this much trouble, I'll have no choice but to apologize.
真相を知った以上、追及せずにはすまない。
Now that the truth is out, the matter can't be left without being pursued.
When you can't use it
- する becomes せずにはすまない (not ×しずに). Expresses inevitability driven by social or moral pressure, not mere personal need.
Easily confused with
ざるを得ない ざるを得ない is the broad 'have no choice but to' (obligation by circumstance). ずにはすまない adds social/moral pressure — others won't let it rest unless you do. なければならない なければならない is a neutral 'must'. ずにはすまない frames the action as unavoidable because the situation or society won't permit otherwise. ずに済む ずに済む is the opposite — 'get by *without* having to ~'. ずにはすまない = 'can't get by without ~ing'.
See 〜ずにはすまない in real sentences
Jengo shows 〜ずにはすまない the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled from published Japanese grammar references.