Translation guide
The state of being unable to do something due to lack of ability, legal disqualification, or physical/mental condition. Japanese expressions vary by context: general inability, legal incompetence, or medical impairment.
Expressing that someone is unable to perform a task or function due to insufficient ability or capacity.
Literally 'no ability'. Used for general incapacity or incompetence, often in formal or critical contexts. Can be harsh when applied to people.
彼はその仕事に対して無能だ。
He is incapable of doing that job.
A straightforward phrase meaning 'lacks ability'. Neutral and widely used.
彼にはリーダーとしての能力がない。
He lacks the ability to be a leader.
The potential form of する (to do), meaning 'cannot do'. Simple and common for expressing incapacity in everyday situations.
私は泳ぐことができない。
I am incapable of swimming.
Means 'powerless' or 'helpless'. Emphasizes lack of power or strength rather than skill.
災害の前では人間は無力だ。
Humans are powerless in the face of disaster.
Referring to a person's legal inability to make decisions or manage affairs, often due to mental disability or minority.
Legal term for incapacity or incompetence. Used in contexts like 'legal incapacity' or 'mental incapacity'.
彼は法的に無能力者とみなされた。
He was deemed legally incapacitated.
Specifically refers to lack of capacity to perform legal acts. Used in civil law.
未成年者は行為能力がないとされる。
Minors are considered to lack legal capacity.
Historical legal term for interdiction or legal incompetence. Now replaced by adult guardianship system, but may appear in older texts.
Describing a condition where a person is unable to perform normal activities due to physical or mental impairment.
General term for disability or impairment. Can refer to physical, mental, or intellectual disabilities. Often used in compounds like 身体障害 (physical disability).
彼は身体障害で働けない。
He cannot work due to a physical disability.
Means 'impossible' or 'incapable'. Often used in medical contexts for loss of function, e.g., 勃起不能 (erectile dysfunction).
Medical/technical term for dysfunction or functional incapacity of an organ or system.
English 'incapacity' is often translated as 無能力 or 不能, but these can sound overly formal or technical. In everyday speech, use simpler phrases like できない or 能力がない unless a specific legal or medical context requires precision.
無能 (むのう) implies lack of skill or competence, often with a negative judgment. 無力 (むりょく) implies lack of power or influence, often in a situational context. Choose based on whether the incapacity is about ability or power.
彼は禁治産者として扱われた。
He was treated as a legally incompetent person.
After the accident, he became unable to walk.
腎機能不全と診断された。
He was diagnosed with renal dysfunction.