とんでもありません

Japanese

Etymology

From the adjective とんでもない by replacing ない with ありません.

Interjection

とんでもありません • (tondemoarimasen) 

1. (nonstandard) not at all

Usage notes

Commonly considered a mistake because とんでもない is handled as an adjective in modern Japanese grammar and replacing the ない with ありません to make a polite form is thus a mistake according to the grammar. Although etymologically とんでもない is not a single word but an expression (途でもない), it is used like a single word today except for the non-standard polite forms とんでもありません and とんでもございません.