modality N3 common politewritten
〜難い — hard to ~ / difficult to bring oneself to ~
〜難い ・ がたい
Builds on 連用形（ます形）
Meaning
- hard to ~ / difficult to bring oneself to ~ — it is nearly impossible, often for psychological or emotional reasons
Key sentence
彼の話は信じ難い。
His story is hard to believe.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Verb (masu-stem) | V(stem) + 難い (then conjugates as an i-adjective) | 理解する → 理解し難い / 想像する → 想像し難い |
When: Formal and written or speech-making in tone. It attaches to a limited set of mostly abstract verbs — 信じる, 理解する, 想像する, 表現する, 忘れる, 認める, 近づく — not to everyday physical actions.
Examples
その悲しみは言葉では表現し難い。
That sorrow is hard to put into words.
今の状況では賛成し難い。
Given the current situation, I find it hard to agree.
あの日の光景は今も忘れ難い。
The scene from that day is hard to forget even now.
When you can't use it
- Not used for ordinary physical difficulty. You can't say 食べ難い for food that is awkward to eat; that's 食べにくい. 難い is reserved for things one cannot bring oneself to do or that defy comprehension.
Easily confused with
〜にくい にくい is the everyday word for 'hard to ~,' covering physical and practical difficulty with almost any verb (歩きにくい, 飲みにくい). 難い is literary, emotional/abstract, and limited to a small verb set (信じ難い, 忘れ難い). 〜かねる Both express an inability to do something for non-physical reasons, but かねる is a polite, business-like way to decline on the speaker's own part (賛成しかねます = 'I'm afraid I cannot agree'). 難い describes the difficulty as an objective quality (賛成し難い = 'it is hard to agree').
See 〜難い in real sentences
Jengo shows 〜難い the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled with reference to A Dictionary of Intermediate Japanese Grammar.