이 바뀌었을

when something has changed

→ 이

phrase Uncommon #6,975

when something has changed 이 marks the subject, and 바뀌었을 is typically followed by 때 (“when”) or another word or phrase.

KO: 마음이 바뀌었을 때 알려 주세요.

EN: Please let me know when you’ve changed your mind.