How to say "incapable" in Japanese

• 不能ふのうCommon
  na-adjective, nounThe common word for 'incapable of doing' or 'unable to do', denoting inability to perform an action or task; it can also mean 'impossible'. Choose it when the point is that something cannot be done.
  説得せっとく不能ふのうを感知かんちしてか、黒崎くろさき先生せんせいはため息いきをついて席せきに着ついた。↗

  Perhaps having realized it was impossible to persuade her, Ms. Kurosaki sighed and sat down in her seat.
• ふつつか
  na-adjectiveA less common word, usually written in kana alone, describing a person as inexperienced, inept, or incompetent. It is a marginal match for 'incapable'; for inability to do something, 不能 is the word you want.

Use 不能 for being unable or incapable of doing something; 「ふつつか」 describes a person as inexperienced or inept and is a less common, marginal match for 'incapable'.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 不能ふのうimpossible
• ふつつかinexperienced