English Translation
Have you ever heard her sing on stage?
Have you ever seen how he/she sings on stage?
The sentence is missing a comma, i.e. it should be Widziałeś kiedykolwiek, jak śpiewa na scenie?
The English translation is perfectly fine.
Have you ever heard her sing on stage?
Have you ever seen how he/she sings on stage?
The sentence is missing a comma, i.e. it should be Widziałeś kiedykolwiek, jak śpiewa na scenie?
The English translation is perfectly fine.