Learn Polish: Nie ma gospodyni w domu. - The landlady is not at home.

In Polish, when you want to say that someone or something is physically absent or not in a specific place, you must use nie ma (literally: it does not have) rather than nie jest. This construction always requires the missing person or thing to take the Genitive case.

Since nie ma requires the Genitive case, why doesn't the word gospodyni change its ending?

The word gospodyni is actually in the Genitive case here, even though it looks identical to its dictionary form (the Nominative case). Feminine nouns ending in -yni or -ini have a special declension pattern where the Genitive, Dative, and Locative singular forms are spelled exactly the same as the Nominative.

Is gospodyni only used for a landlady?

No, gospodyni is a versatile word. Depending on the context, it can also mean a hostess of a party, a female farmer, a homemaker, or a housekeeper. It generally refers to the woman in charge of a household or property.

Why do we say w domu for at home?

To say that someone is at home, Polish uses the preposition w (in/inside) followed by the Locative case. For the noun dom (house/home), the Locative form is domu. So w domu is the fixed, natural way to express being at home.