When to use to promise in Korean
Korean: 약속하다[ yak-sok-ha-da ]

When to use it
약속하다 means to promise. You use it when you tell someone that you will do something or that you will not do something. It is often used with family, friends, teachers, or other people when you want to show you will keep your word.
Example sentences
엄마에게 일찍 집에 오겠다고 약속했어요.
I promised my mom I would come home early.
선생님께 숙제를 꼭 하겠다고 약속했어요.
I promised my teacher I would definitely do my homework.
친구에게 비밀을 지키겠다고 약속했어요.
I promised my friend I would keep the secret.
동생과 공원에서 싸우지 않겠다고 약속했어요.
I promised my younger sibling not to fight at the park.
가게 주인은 내일 물건을 보내겠다고 약속했어요.
The shop owner promised to send the item tomorrow.
나는 여행 중에 매일 전화하겠다고 약속했어요.
I promised I would call every day during the trip.