When are the months introduced before this?
You learn them in this lesson.
when do you use jest rather than to? Why would the sentence not read "Kwiecień jest miesiąc."
Kwiecień jest miesiącem.
Difference between jest and to? Is it because April is like a proper noun? Or do proper nouns not exist in Polish?
That's so confusing, because "Květen" means May in Czech :D