This is the 9233rd most frequent Korean word.
걸려있어서
"걸려있어서" means "is hanging" or "is stuck," depending on context.
걸려있어서 is used to indicate that something (the curtain) is hanging.
문 앞에 커튼이 걸려있어서 안이 보이지 않았어요.
There was a curtain hanging at the door, so you couldn't see inside.
걸려있어서 describes the phone being in a state of engagement.
전화가 통화 중으로 걸려있어서 연결이 안 됐어요.
The phone was engaged in a call, so the connection couldn't be made.
걸려있어서 is used to describe an advertisement being displayed.