This is the 20th most frequent Indonesian word.
mereka
"They."
In this sentence, 'mereka' refers to a group of people as the subject of the action.
Mereka sedang belajar di perpustakaan.
They are studying in the library.
In this case, 'mereka' serves as the indirect object of the verb 'memberi' (to give).
Guru memberi mereka tugas untuk besok.
The teacher gave them an assignment for tomorrow.
Here, 'mereka' is used as a possessive pronoun, indicating ownership.