Questions & Answers about После работы я зайду в аптеку и заодно куплю хлеб.
Because после requires the genitive case.
- работа = work in the dictionary form
- работы = genitive singular
So после работы literally means after work.
This is a very common pattern:
- после урока = after the lesson
- после обеда = after lunch
- после фильма = after the film
Here работы is genitive singular, not plural. The phrase means after work as a general activity or workday, not after the works or after jobs.
Russian often uses the singular in expressions like this:
- после школы = after school
- после университета = after university
- после работы = after work
So this is just the normal idiomatic way to say it.