Ways to say it
| Japanese | Romanization (Wiktionary) | IPA | Note |
|---|---|---|---|
| とんでもない | tonde mo nai | [tõ̞nde̞mo̞na̠i] (narrow) | |
| いいえ | iie | [iːe̞] (narrow) | informal |
とんでもない is the conventional reply when someone thanks you and you want to brush the thanks aside. Literally it means something like it is unthinkable or out of the question, so you are saying that you do not deserve the thanks.
Which one should you use?
いいえ (iie) is a simpler, more casual reply. In speech it is very often doubled as いえいえ to soften the reply. Do not confuse these replies with 全然, which means not at all in the sense of degree, as in I don't understand at all. 全然 negates a verb or adjective, while とんでもない is a social reply to gratitude.
Is there a formal and an informal way to say it?
いいえ is the informal choice. Adding です to make とんでもないです is more polite and suits a reply to a superior or someone you do not know well.
Related words
How does it change in a sentence?
To make the reply more polite, add です after it to get とんでもないです.
How do you pronounce it?
It is romanized as tonde mo nai.
What mistakes should you avoid?
Do not answer thanks with 全然 alone. Use とんでもない or いえいえ to deflect thanks, and keep 全然 for saying not at all about an amount or degree.
When do people say it?
Modesty matters in Japanese conversation, so people commonly wave off thanks or praise rather than simply accepting it.
Did you know?
- The modern slang term トンデモ ('tondemo'), used to describe something outrageous or absurd, is actually a shortened version of the polite phrase とんでもない.
- When replying with いえいえ, speakers often accompany the words with a small, repetitive waving motion of the hand to physically 'brush off' the gratitude.
Examples in context
- 「あ、どうも。」「いえいえ、こちらこそ。」"Oh, thanks." "Not at all, I should thank you."The reply いえいえ softens the response, and こちらこそ adds that the speaker should be the one giving thanks.
- 「ありがとうございます。」「いやいや、とんでもないです。」"Thank you." "No no, not at all."Here いやいや is followed by the polite とんでもないです to brush off the thanks.
- 彼の主張は全く事実と異なっています。His claim is entirely different from the truth.
- 私はその話を決して信じません。I absolutely do not believe that story.
- 彼は一切関与していません。He is not involved at all.
- 全然心配しなくていいよ。You don't have to worry at all.
- この料理は全然おいしくない。This dish is not tasty at all.
- とんでもないです。tondemonai desu.Not at all.
Example conversation
Misaki thanks Hiroto for helping her carry heavy bags.
- 美咲 Misaki荷物を持ってくれて、ありがとうございます。nimotsu o motte kurete, arigatou gozaimasu.Thank you for carrying my bags.
- 大翔 Hirotoとんでもないです。お役に立てて良かったです。tondemonai desu. o-yaku ni tatete yokatta desu.Not at all. I'm glad I could help.
- 美咲 Misaki本当に助かりました。hontou ni tasukarimashita.You were a real lifesaver.
- 大翔 Hirotoいえいえ、また何かあれば言ってください。iie iie, mata nanika areba itte kudasai.No problem, please let me know if you need anything else.
Sources
- Wiktionary, “not at all” translations and entries とんでもない, いいえ, CC BY-SA 4.0, dump of 2026-09-26.
- Word origins: Wiktionary entries いいえ, とんでもない, CC BY-SA 4.0.
- Example sentences: Wiktionary CC BY-SA 4.0.
