Not Difficult — Nearly Impossible
がたい is far stronger than にくい. It means the thing can barely be done at all, usually for psychological or moral reasons.
- 信じがたい話です。(That's a story I can hardly believe.)
Against にくい
| Pattern | Force |
|---|---|
| にくい | physically awkward — 書きにくいペン |
| がたい | barely possible — 想像しがたい |
にくい attaches to almost any verb. がたい attaches to a small, fixed set, nearly all of them mental: 信じる, 想像する, 理解する, 忘れる, 近寄る, 耐える, 捨てる.
×食べがたい is wrong. Eating is not a moral difficulty; use 食べにくい.
忘れがたい — A Compliment
Some がたい compounds are positive: 忘れがたい思い出 is an unforgettable memory, and 得がたい経験 is a rare and valuable experience.
Register
Formal and written. It behaves as an い-adjective: 信じがたかった, 信じがたい話.
