ないではすまない・
済む is "be over and done with". After a negative verb, the stiff, written ずにはすまない says it won't be over unless the thing is done: no getting out of it. After a noun, the everyday では済まない says that much won't be the end of it.
The accident was caused by a defect in the product, so the maker can't get out of compensating the victims.
A lie that affects people's safety can't be laughed off as a joke. You may be held responsible.
Can't get out of doing
Verb ない-form: ない → ずにはすまない／ないではすまない する → せずにはすまない
謝らない → 謝らずにはすまない, 謝らないではすまない. The same meaning; ずには is the more common. Also written 済まない.
Won't end at that
Noun + では済まない／では済まされない
Also after quoted words, or a verb with だけ: 謝るだけでは済まない. Polite 済みません.
Can't get out of it: ずにはすまない
Harm was done, or a promise made, and what is right, or what people expect, leaves no way out. So the verbs are ones like 謝る, 補償する, 責任を取る and 説明する, and the reason usually comes first, with 以上 or のだから.
The company's mishandling caused the customer a loss, so it can't get out of making a formal apology.
Now that the accounting fraud has come to light, the management can't get out of taking responsibility.
A researcher who falsified research data will not escape harsh criticism from the academic world.
After a passive, it is what someone won't escape.
Won't end at that: では済まない
The noun is what getting off lightly would look like: a joke, an apology, a warning, a fine. What it will really take often comes next. Said to someone's face, it tells them trouble is coming.
Break the rules again, and next time it won't end with a warning. Your qualification may be suspended.
A fall from this height would mean worse than an injury.
If the department head finds out, you won't get off lightly.
ただでは済まない is a set warning: there will be a price to pay.
In a job that deals with laws and regulations, "I didn't know" won't do. You will also be held responsible for failing to check.
Quoted words: an excuse that won't do.
With 済まされない it is stronger: people won't let it pass.
You can't hurt someone and then pass it off with "it was a joke".
ずにはすまない and ずにはおかない
With this much damage done, the company can't get out of bringing the cause of the accident to light.
"Can't get out of it": duty pushes the company. It would rather not.
However many years it takes, I will not rest until I have brought the cause of the accident to light.
"Won't leave it undone": I do the pushing. Nobody is making me.
Close neighbours
"Won't leave it undone": the subject does the pushing. A person will not rest until it is done, or a thing can't fail to stir people.
That quiet final scene can't fail to move an audience deeply.
ずにはいられないN2
"Can't help doing": the push comes from inside, a feeling too strong to hold back.
When I saw that photo, I couldn't help laughing.
ずに済むN2
Without は, and in the positive, it is the other way around: you are spared the thing, and glad of it.
A friend lent me one, so I didn't have to buy it.
What people say: "I can't very well not". Duty, or what people would think, rules out leaving it undone.
Since I made a promise, I can't very well skip tomorrow's meeting.
Check yourself
1Which one fits?
行きたくは
Choose an answer to see why.
2What does this mean?
スピード違反も、
Choose an answer to see why.
3What happens next?
友だちの
Choose an answer to see why.
More sentences
Having given residents wrong information, the city can't get out of explaining how it happened.
Having broken the contract unilaterally and caused the other side a loss, there is no getting out of paying the penalty.
This misconduct won't end with one person being disciplined. The management system itself needs to be reviewed.
A serious data leak won't be settled by an apology from the person in charge. The company needs to offer compensation for the damage and show how it will stop it happening again.
Paying for the repairs won't be the end of it. The cause of the accident has to be made public.
We have lost customers' data, so promising it won't happen again will not be enough. We also need to explain the cause.
Polite: 済みません.