This is the 12938th most frequent Turkish word.
kalacaklarını
"Kalacaklarını" means "that they will stay."
Here, 'kalacaklarını' serves to express the reported intent of the students to remain somewhere, conveyed within an indirect speech structure.
Öğrenciler dersten sonra kütüphanede kalacaklarını belirttiler.
The students stated they would stay at the library after the lesson.
In this sentence, 'kalacaklarını' indicates a reported statement about the future action of staying by the guests. It is formed by the root verb 'kal-' (to stay), future tense suffix '-acak', possessive '-lar', and the object marker '-ını'.
Misafirler bu gece otelde kalacaklarını söylediler.
The guests said they would stay at the hotel tonight.
In this example, 'kalacaklarını' communicates the intention of staying in the future reported by the mentioned friends.