This is the 384th most frequent Catalan word.
estaven
"Estaven" means "they were" in English.
Here, "estaven" is used as the imperfect form of 'estar,' indicating a past action in progress (the students being at the library).
Els estudiants estaven a la biblioteca estudiant per a l'examen.
The students were at the library studying for the exam.
Here, "estaven" is part of a past continuous structure, describing an ongoing action in the past ('estar' + Gerund).
Quan vaig entrar, els gossos estaven dormint tranquil·lament.
When I entered, the dogs were sleeping peacefully.
Here, "estaven" describes the state of the children in the past, using 'estar' to denote a temporary state or condition.