This is the 26th most frequent Greek word.
οποία
The Greek word "οποία" means "which" or "whichever" (feminine form).
Here, 'οποία' serves as a relative pronoun referring to the teacher, functioning as the object of respect in the subordinate clause.
Είναι μία εκπαιδευτικός, την οποία όλοι σέβονται.
She is a teacher whom everyone respects.
In this case, 'οποία' is used as a relative pronoun, introducing the reason behind the delay.
Δεν γνωρίζω την αιτία για την οποία καθυστέρησε.
I do not know the reason for which she was late.
In this sentence, 'οποία' is used as a relative pronoun referring to the library, indicating the place where the action takes place.