Questions & Answers about Po zmroku wolę zostać w domu.
Po zmroku means after dark / after dusk.
The noun here is zmrok = dusk, twilight. After the preposition po in this time expression, Polish uses the locative case, so zmrok becomes zmroku.
This pattern is very common:
- po pracy = after work
- po obiedzie = after lunch
- po zmroku = after dark
So this is not a random form: it is the normal case required by po here.
Not exactly.
- po zmroku means once it has become dark
- wieczorem means in the evening
So po zmroku is more specific. In summer, for example, evening can start before it is actually dark, so wieczorem and po zmroku are not always the same time.
If the speaker chooses po zmroku, they are specifically focusing on the fact that it is dark outside.