This is the 12101st most frequent Korean word.
누구일지를
"누구일지를" translates to "who it will be" or "whose it will be" in English.
The word '누구일지를' is used as part of a question to inquire about the identity of the person who wrote the letter.
이 편지를 쓴 사람이 누구일지를 알 수 있을까요?
Can we know who wrote this letter?
Here, '누구일지를' refers to determining the person who holds the role of actor.
그 배우가 누구일지를 알아내기 위해 우리는 인터넷을 검색했어요.
To find out who the actor is, we searched the internet.
In this sentence, '누구일지를' is used speculatively to ponder the identity of a person in a photo.