Questions & Answers about Ten nowy budynek ma dwadzieścia pięć pięter.
Why does the word for "floors" change to pięter here?
After numbers 5 and above (like dwadzieścia pięć), Polish requires the following noun to be in the Genitive plural case. The base word is piętro (a neuter noun meaning "floor"), and its Genitive plural form is pięter.
Since this lesson covers ordinal numbers, how would I change this to say "the twenty-fifth floor"?
You would use the ordinal number forms: dwudzieste piąte piętro. Notice that when using ordinal numbers ("twenty-fifth"), the number acts like a normal adjective and the noun stays in the basic Nominative case (piętro), instead of jumping to the Genitive plural like it does with the regular quantity 25.
Why do we use Ten nowy instead of To nowe for the building?
Budynek (building) is a masculine inanimate noun. Because of this, the words for "this" and "new" must match its gender, giving us ten nowy. You would use to nowe for neuter nouns, such as to nowe piętro (this new floor).
Does the verb ma (has) affect the case of the number dwadzieścia pięć?
Yes, the verb mieć (to have) requires its direct object to be in the Accusative case. Luckily, for numbers describing everyday things (inanimate nouns), the Accusative form looks exactly the same as the basic dictionary form. So dwadzieścia pięć doesn't change its spelling here.