Questions & Answers about Suma ubezpieczenia jest wysoka.
Because ubezpieczenia is in the genitive singular. After a noun like suma (sum, amount), Polish often uses another noun in the genitive to mean of ....
So:
- suma = sum / amount
- ubezpieczenia = of insurance
Literally, the phrase is structured like sum of insurance.
This is very common in Polish:
- numer telefonu = phone number literally number of phone
- koniec dnia = end of the day
- cena biletu = ticket price
Suma is in the nominative singular.
It is the subject of the sentence:
- Suma ubezpieczenia = the subject
- jest = is
- wysoka = describes the subject
You can think of the basic structure as:
[subject] + [is] + [adjective]
So suma stays in the nominative because it is the thing being talked about.