This is the 6030th most frequent Korean word.
서명했다
"Signed."
Here, '서명했다' means 'signed' as in a legal or formal document.
그는 중요한 계약서에 서명했다.
He signed the important contract.
In this sentence, '서명했다' is used to indicate the act of signing a book, often as a form of autograph.
작가는 팬미팅에서 책에 서명했다.
The author signed books at the fan meeting.
This usage emphasizes the requirement of the signature on the document, using '서명했다' to denote the fulfillment of this need.