Compound Ordinal Numbers
In Polish, when forming compound ordinal numbers like "twenty-first" or "twenty-second," both the tens and the units act as ordinal adjectives. Both words must agree with the noun they describe in gender, number, and case.
Gender Agreement
Because both parts of the compound number are adjectives, they change their endings to match the noun's gender. For a feminine noun like sala (room), both words take the feminine nominative -a ending (dwudziesta czwarta).
For a neuter noun like piętro (floor), both words take the neuter nominative -e ending. The word for "thirtieth" (trzydziesty) becomes trzydzieste.
Placements and the Locative Case
When talking about exact placements, such as being on a floor (na) or in a row (w), you must use the locative case. Crucially, both parts of the compound ordinal number take the locative ending.
For masculine and neuter nouns, both the tens and the units take the locative adjective ending -ym.
To sound more natural when describing where rooms, offices, or objects are placed in a building, you can use the verb znajdować się (to be located).
