At a glance
～ではすまない means "X is not enough" or "it won't end with just X". It is used in serious situations where the speaker feels a bigger response or a heavier consequence is needed.
Noun + ではすまない
Verb (dictionary form) + だけではすまない
謝るだけでは済まない。 Just apologizing won't be enough.
How to form it
済まない is the negative of 済む "to be settled, to be enough". では is で (means, extent) plus contrastive は.
| Attaches to | Form | Example |
|---|---|---|
| Noun | Noun + では済まない | 謝罪では済まない |
| Verb | Dictionary form + だけでは済まない | 謝るだけでは済まない |
| Casual speech | では becomes じゃ | ごめんじゃ済まない |
In polite speech it is often followed by でしょう or と思います: 謝罪では済まないと思います。