This is the 9427th most frequent Korean word.
결정한다
"결정한다" means "to decide."
In this sentence, '결정한다' indicates the action of making a decision regarding the plan.
그는 내일까지 계획을 결정한다.
He decides the plan by tomorrow.
Here, '결정한다' refers to making a decision about the weekend trip.
우리는 이번 주말 여행을 결정한다.
We decide on the travel for this weekend.
In this context, '결정한다' is used to signify the determination of essential matters.