Did you know that we use the imperfective verbal aspect when an action is “revoked”?
Ты открывал окно? Did you open the window? (The window was open, but it is shut now), Imperfective.
Ты открыл окно? Have you opened the window? (The window is still open), Perfective.
Ты брал мою ручку? Did you take my pen? (He took it, but he already returned it), Imperfective.
Ты взял мою ручку? Have you taken my pen? (The second person still has the pen), Perfective.