This is the 19311th most frequent Korean word.
알기
"알기" means "understanding" or "knowing."
Here, '알기' is used as a gerund, meaning 'understanding'.
그 문제를 알기가 어렵습니다.
It is difficult to understand that issue.
In this sentence, '알게 되었다' utilizes '알기' in the context of realizing or coming to know.
그의 행동을 보고 진심을 알게 되었다.
By observing his behavior, I came to know his true feelings.
Here, '알기' represents 'finding out about' or 'knowing' the qualities of a good friend.