Questions & Answers about Я открыл календарь на ноутбуке.
Why does it use открыл and not открывал?
Открыл is perfective—one completed action with the result achieved. Открывал is imperfective—process, repeated/habitual action, or background (“was opening/used to open”) and doesn’t guarantee the result.
What case is календарь, and why isn’t it календаря?
It’s the direct object of открыть (“to open what?”), so accusative. Masculine inanimate nouns keep nominative form in the accusative, so календарь stays календарь. Календаря is genitive.
Why на ноутбуке and not в ноутбуке?
With devices, Russian typically uses на + prepositional to mean “on/using” a device: на ноутбуке/на компьютере/на телефоне. В ноутбуке suggests physically inside the laptop—unnatural here.
What about на ноутбук without the final -е?
На + accusative (e.g., на ноутбук) means motion “onto” a surface (“put it onto the laptop”). For location/using a device you need на ноутбуке (prepositional).
What gender information is in открыл?