When to use to find out in Korean
Korean: 알아내다[ al-a-nae-da ]

When to use it
알아내다 means to find out or discover information after looking, asking, or thinking. You use it when something was not known at first, but then you learn the answer. It is common for things like times, prices, names, places, or the reason for something.
Example sentences
엄마가 쿠키를 어디에 숨겼는지 알아냈어요.
I found out where Mom hid the cookies.
친구와 함께 수학 문제의 답을 알아냈어요.
I found out the answer to the math problem with my friend.
지도를 보고 공원 가는 길을 알아냈어요.
I found out the way to the park by looking at the map.
친구와 이야기하다가 그의 생일을 알아냈어요.
I found out his birthday while talking with my friend.
가게에 전화해서 가격을 알아냈어요.
I found out the price by calling the store.
인터넷으로 기차 시간을 알아냈어요.
I found out the train time on the internet.