不能(ふのう)

Composed of 不(ふ) (not) + 能(のう) (able). Most often used as the second element of a compound to negate a capability. Functions as a na-adjective when modifying a noun (予測(よそく)不能(ふのう)な〜) and as a noun-predicate (修理(しゅうり)不能(ふのう)だ).

Compounds

• 修理(しゅうり)不能(ふのう): impossible to repair
• 予測(よそく)不能(ふのう): unpredictable
• 使用(しよう)不能(ふのう): unusable
• 再生(さいせい)不能(ふのう): non-renewable; cannot be played back
• 回復(かいふく)不能(ふのう): irrecoverable
• 実行(じっこう)不能(ふのう): unworkable; infeasible

Common patterns

• Noun + 不能(ふのう)な + Noun: an unX-able Y
• Noun + 不能(ふのう)になる: to become unable; to be disabled

Similar words

• 不可(ふか): not allowed; impossible — emphasizes prohibition or unfeasibility (使用(しよう)不可(ふか) not permitted to use)
• 不可能(ふかのう): impossible — stand-alone na-adjective; broader use
• 困難(こんなん): difficult — implies it is hard but not impossible