This is the 14342nd most frequent Korean word.
못해낼
"못해낼" means "cannot accomplish" or "unable to do."
못해낼 is used here to express the inability or impossibility of successfully carrying out an action due to difficulty.
그는 너무 어려운 문제라서 못해낼 것 같아요.
He seems unlikely to complete it because the problem is too difficult.
못해낼 is highlighting the lack of capability or readiness to accomplish a challenging task in this context.
아이들은 이 복잡한 퍼즐을 아직 못해낼 거야.
The children will probably not be able to solve this complex puzzle yet.
못해낼 is indicating a personal limitation or capacity preventing successful completion of a job or task.