to repay debt or return a favor
When to use
Repaying debt, Returning favor, Compensating effort
The nuance
갚다 is used when repaying debts, favors, or efforts. It is mainly used in contexts of fulfilling financial or non-financial obligations.
갚다 (gap-da, gapda) · 돌려주다 (dol-ryeo-ju-da, dolryeojuda)
갚다 is used for repaying debts or returning favors, while 돌려주다 refers to giving back borrowed items or money to their original owner.

One lane per word — no nested boxes, just the gist.
to repay debt or return a favor
When to use
Repaying debt, Returning favor, Compensating effort
The nuance
갚다 is used when repaying debts, favors, or efforts. It is mainly used in contexts of fulfilling financial or non-financial obligations.
to return borrowed items or money to the original owner
When to use
Returning items, Returning borrowed money, Recovering lent goods
The nuance
돌려주다 is used for the act of giving back borrowed items or money to their original owner. It focuses on the physical act of returning borrowed things.
나는 친구에게 빌린 돈을 다 갚았다.
na-neun chin-gu-e-ge bil-rin don-eul da gap-ass-da., na neun chin gu e ge bil rin don eul da gap ass da.
Repaying borrowed money (debt) fits '갚다' properly.
친구에게 빌린 책을 돌려주었다.
chin-gu-e-ge bil-rin chaek-eul dol-ryeo-ju-eoss-da., chin gu e ge bil rin chaek eul dol ryeo ju eoss da.
Returning a borrowed item to its owner fits '돌려주다'.
나는 친구에게 빚을 돌려주었다.
na-neun chin-gu-e-ge bij-eul dol-ryeo-ju-eoss-da., na neun chin gu e ge bij eul dol ryeo ju eoss da.
For repaying debt, '갚다' should be used; '돌려주다' is incorrect.
빌린 돈을 갚았다.
bil-rin don-eul gap-ass-da., bil rin don eul gap ass da.
Repaying borrowed money is correctly expressed by '갚다'.
빌린 돈을 돌려주었다.
bil-rin don-eul dol-ryeo-ju-eoss-da., bil rin don eul dol ryeo ju eoss da.
Physically returning borrowed money fits '돌려주다'.
은혜를 돌려주었다.
eun-hye-reul dol-ryeo-ju-eoss-da., eun hye reul dol ryeo ju eoss da.
Returning a favor requires '갚다'; '돌려주다' is unnatural.
책을 갚았다.
chaek-eul gap-ass-da., chaek eul gap ass da.
For items like books, '돌려주다' is correct; '갚다' is wrong.
노력한 만큼 은혜를 갚아야 한다.
no-ryeok-han man-keum eun-hye-reul gap-a-ya han-da., no ryeok han man keum eun hye reul gap a ya han da.
Repaying a favor or kindness is appropriately expressed by '갚다'.
Which word should you use when returning a borrowed book to a friend?
Which word fits the expression 'to repay debt'?
Which word is appropriate for physically returning borrowed money?