Questions & Answers about После звонка я быстро вышел из класса и пошёл домой.
Because после requires the genitive case.
- звонок = nominative singular
- звонка = genitive singular
So:
- после урока = after the lesson
- после обеда = after lunch
- после звонка = after the bell
This is a very common pattern in Russian: certain prepositions always force a particular case, and после always takes the genitive.
It can mean either a ring / bell or a phone call, depending on context.
In this sentence, because we have из класса and домой, the natural meaning is the school bell:
- После звонка = After the bell
A native speaker would usually understand this as after the class bell rang.