Translation guide
The English verb 'repay' covers returning money, reciprocating kindness or harm, and compensating effort. Japanese uses different verbs depending on what is being repaid and the nuance.
To give back money that was borrowed or owed.
The standard verb for repaying a loan or debt. Used in financial contexts.
I repay my loan every month.
A general verb for returning something, including money. More casual than 返済する.
I forgot to repay the money I borrowed.
To do something good in return for someone's help or kindness.
Literally 'to return a favor'. The most natural way to express repaying kindness.
I will definitely repay your kindness someday.
To repay, reward, or reciprocate. Often used in set phrases like 恩に報いる (repay a kindness). Slightly formal.
A lighter, more casual way to say 'repay a favor', often for small kindnesses or gifts.
Please let me repay you in some way.
To retaliate or get revenge for a wrong done to you.
To get back at someone, to retaliate. Common for personal revenge.
I'll repay him for what he did.
To take revenge. Stronger and more dramatic than 仕返し. Often used in stories.
He repaid his family's enemy.
An idiom meaning 'an eye for an eye', implying repayment in kind. Used in discussions of justice.
The idea of repaying in kind is problematic.
To reward or compensate for effort, often with results or recognition.
To return a visit or phone call.
返す is a general verb for returning objects or money. 返済する is specifically for repaying debts or loans and sounds more formal.
While 返す can be used for money, it is not used for repaying favors or kindness. Use 恩返しをする or 報いる instead.
Repay a favor (literal translation, avoid).
ご恩に報いるために努力します。
I will work hard to repay your kindness.
彼の努力は十分に報いられた。
His efforts were fully repaid.
Repay a favor.