〜だに

Formality Level: Literary / Archaic formal — classical literature, formal written Japanese, elevated literary fiction, proverbs

Classical/Literary Origin: だに is a classical Japanese particle of emphasis, related to the modern さえ and すら. In classical Japanese (奈良時代〜平安時代), だに indicated the minimal case: "even X (the least of all cases)." It appears in the Man'yōshū and Genji Monogatari. In modern Japanese it has two residual uses: one with verbs of thought/feeling (想像だにしない, 思いだにしない) emphasising that something cannot even be imagined, and one with 〜だにしない emphasising that not even the smallest action was performed. Both uses are literary and rarely appear outside of formal writing.

Structure

Form	Meaning	Example
Noun + だに + verb of cognition (neg.)	Cannot even ~	想像だにしない
Verb (連用形/ます-stem) + だに	Even just doing ~	思い出すだに恐ろしい
Set phrase: 〜だにしない	Not even ~	微動だにしない

The most common modern fixed expressions are:

想像だにしない / 想像だにできない — "cannot even imagine"
思いだにしない — "not even think of"
微動だにしない — "not budge even a millimetre; perfectly still"
〜するだに〜 — "merely thinking of ~ is enough to make one feel ~"

Meaning

"Even ~" — with a strong emphasis on the minimal or extreme nature of the case.

In the pattern 〜だにしない, the nuance is: "not even the slightest ~." 微動だにしない means the subject does not move even a tiny bit.

In the pattern 〜するだに〜, the nuance is: "merely the act of ~ is enough to produce the stated effect." 想像するだに恐ろしい = "it is frightening merely to imagine it" — the implication is that actually experiencing it would be far more intense.

This is an extremely literary pattern. Modern learners encounter it primarily in reading classical or literary modern Japanese. Using it in speech would sound affected and archaic except in very deliberate formal or literary contexts.

Example Sentences

Japanese	English
あれほどの惨状は、想像だにしなかった。	I could not even have imagined such devastation.
彼はいかなる批判にも微動だにしなかった。	He did not budge even a millimetre in the face of any criticism.
思い出すだに恐ろしい体験だった。	It was an experience so frightening that merely recalling it is terrifying.
かつて、これほど世界が変わるとは、誰も考えだにしなかっただろう。	At the time, no one could even have conceived that the world would change so drastically.
その名を聞くだにぞっとする、と彼は語った。	"Merely hearing that name sends a shiver through me," he said.
彼女は激しい嵐の中でも表情一つ変えず、微動だにしなかった。	Even in the fierce storm, she did not change her expression or move an inch.

Common Mistakes

Using だに in modern casual contexts: だに is archaic/literary and sounds bizarre or comical in casual speech. Use さえ or すら for "even" in daily conversation.
Confusing 〜だに with 〜だって or 〜さえ: While all three can express "even," だに is purely literary and does not appear in colloquial Japanese. さえ and でさえ are the standard modern equivalents.
Applying だに to broad verbs of action: だに pairs naturally with verbs of thought, perception, and minimal physical movement (想像する, 思う, 微動, 聞く). Applying it to ordinary action verbs (食べるだに, 行くだに) sounds unnatural even in formal writing.

Compare With

Pattern	Register	Meaning	Key Difference
〜だに	Literary/Archaic	Even (emphatic minimal case)	Archaic; restricted to fixed expressions and literary prose
〜さえ	All registers	Even ~	Modern standard equivalent; used in speech and writing
〜すら	Formal/Written	Even ~ (often with negative)	More formal than さえ but far less archaic than だに
〜でさえ	Semi-formal	Even ~	Emphasised form of さえ; common in formal writing