だに / だにしない

The particle だに is a classical/literary expression that emphasizes the extremity of something, typically meaning "even" or "just". It appears primarily in two patterns:

だに – "even just ~"

When used with verbs like そうぞう想像する (to imagine), おもう思う (to think), or かんがえる考える (to consider), だに emphasizes that even merely doing that mental action is overwhelming, frightening, or otherwise remarkable. The verb is typically in its stem (連用形) form before だに.

This pattern conveys that the reality must be far more extreme than what one can merely imagine or think about.

だにしない – "not even ~"

When combined with しない, the pattern ～だにしない means "does not even ~", expressing that someone fails to do even the minimum expected action. Common collocations include びどう微動だにしない (does not budge even slightly), ゆめ夢だにしない (does not even dream of), and よそう予想だにしない (does not even anticipate).

Key points

• だに is highly literary and formal. It is rarely used in casual conversation but appears in literature, news, and formal writing.
• The most common fixed expressions are 想像するだに, 微動だにしない, 夢だにしない, and 予想だにしない. Outside of these set phrases, free usage is uncommon in modern Japanese.
• Do not confuse だに with the particle すら or さえ. While all three can mean "even," だに is far more restricted in usage and carries a distinctly literary tone.