What is the meaning of tondemonai?
It seems like tondemonai has several meanings as I always heard Japanese said that in different situations in the drama. I am quite confused when to use it.
Hi Mike, yes you are right that there are many meanings for the word とんでもない (tondemonai). Basically it has the following meanings:
(giron wa shidaini tondemonai houkou ni susunde itta)
Meaning: The discussion has gradually gone into an unexpected direction.
2. Outrageous, Ridiculous, Terrible.
とんでもない値段 (tondemonai nedan)
Meaning: An outrageous price.
とんでもない話 (tondemonai hanashi)
Meaning: An ridiculous story.
3. No kidding.
It's used when you think someone must be joking on what he said.
4. No way, Absolutely not.
It's used when you strongly denied what someone said to you. For example,
A: 君の車を貸してくれない？ (kimi no kuruma wo kashite kurenai?)
B: とんでもない (tondemonai)Meaning
A: Can I borrow your car?
B: No way.
5. All the above meanings are used negatively. However, on the other hand another meaning of it is commonly used in keigo (honorific form) like: "Not at all", "It's ok", "No worries". For example,
A: いろいろとありがとうございました (iroiro to arigatou gozaimashita)
B: いえいえ、とんでもないです (ieie, tondemonai desu)Meaning
A: Thank you very much for all your helps.
B: Not trouble at all!
There is one more point to take note that tondemonai is an i-adjective, not a verb. I think even some native Japanese used it wrongly thinking that it is a verb and say とんでもありません (tondemo arimasen) or とんでもございません (tondemo gozaimasen) in order to make it sounds more polite.
They probably think that the ending part of it is ない (nai), just like nai-form of a verb. Therefore they think that it should be ok to change it to "arimasen" or "gozaimasen" in honorific form.
とんでもない (tondemonai) is one word by itself, just like つまらない (tsumaranai - boring) and あぶない (abunai - dangerous). You cannot say つまらありません (tsumara arimasen) or あぶございません (abu gozaimasen). There are no such Japanese words.
If you want to be more polite, you can say とんでもないことです (tondemonai koto desu) or とんでもないことでございます (tondemonai koto de gozaimasu).
Hope this helps,