Translation guide
The English word 'voluntary' describes actions done freely, without being forced or paid. In Japanese, the most natural expression depends on whether you are emphasizing free will, lack of obligation, unpaid work, or a voluntary organization.
Expressing that an action is done willingly, without external pressure or compulsion.
A common adjective meaning 'spontaneous' or 'voluntary', emphasizing that the action comes from one's own initiative.
彼の自発的な申し出に感謝した。
I was grateful for his voluntary offer.
Often used in formal or legal contexts to mean 'optional' or 'at one's discretion', implying no obligation.
参加は任意です。
Participation is voluntary.
Literally 'by one's own will', this phrase clearly emphasizes personal choice.
彼は自分の意思でその仕事を引き受けた。
He took on the job voluntarily.
Means 'willingly' or 'on one's own accord', often used when someone steps forward to do something.
彼女は自ら進んで手伝ってくれた。
She voluntarily helped me.
Referring to work done without payment, often for a cause or organization.
The most common term for volunteer work or a volunteer. Used as a noun or with する to mean 'to volunteer'.
週末にボランティアをしている。
I do voluntary work on weekends.
Means 'unpaid' or 'without compensation'. Used to describe voluntary work in a more formal way.
彼は無償の奉仕活動に参加した。
He participated in voluntary service activities.
Describing an organization run by volunteers rather than professionals or paid staff.
Standard term for a voluntary organization or volunteer group.
そのボランティア団体は地域の清掃活動を行っている。
The voluntary organization carries out local cleanup activities.
A legal term for an unincorporated association, often used for voluntary groups without legal personality.
このサークルは任意団体として活動している。
This circle operates as a voluntary association.
Referring to bodily movements or actions that are controlled by the will.
Used in medical or biological contexts to describe voluntary muscle movements.
随意筋は意識的に動かせる筋肉だ。
Voluntary muscles are muscles that can be moved consciously.
自発的 emphasizes spontaneity and personal initiative, while 任意 is more about the absence of obligation or rules. Use 自発的 for actions driven by inner will, and 任意 for optional participation or choices.
自発的に手を挙げた。
I raised my hand voluntarily (on my own initiative).
参加は任意です。
Participation is voluntary (not mandatory).
The English word 'voluntary' is sometimes directly borrowed as ボランタリー, but this is not natural Japanese. Use 自発的, 任意, or ボランティア depending on context.