Learn Polish: Szefowa musi wyjaśnić problem kelnerce. - The female boss must explain the problem to the waitress.

Feminine nouns ending in -a usually take the ending -e in the dative case. However, adding this -e triggers a spelling change called a consonant mutation. For nouns ending in -ka, the k changes to a c. Therefore, kelnerka becomes kelnerce (to the waitress).

Why is kelnerce in the dative case here?

The dative case is used for the indirect object of a sentence, which is usually the person receiving something. In this sentence, the waitress is receiving the explanation. Where English uses the word "to" ("to the waitress"), Polish simply uses the dative case ending.

Problem is the direct object being explained, so why doesn't it have an accusative case ending?

It actually is in the accusative case! Problem is a masculine inanimate noun (a masculine word for a non-living thing). For these types of nouns, the accusative form looks exactly the same as the basic dictionary (nominative) form.

How do you form the feminine version of the word for boss?

Szefowa is the feminine form of szef (boss). Polish frequently adds the suffix -owa to masculine titles or roles to create the female equivalent. While historically this often meant "wife of the boss", today it simply means a female boss.

Why use the verb instead of ?