Изучала ли Пэм русский язык, прежде чем она переехала в Москву? - Да.
Did Pam study Russian before she moved to Moscow? - Yes, she did.
Had Pam studied Russian before she moved to Moscow? - Yes, she hadn't.
Had Pam studied Russian before she moved to Moscow? - Yes, she had.
Has Pam studied Russian before she moved to Moscow? - Yes, she has.