Ordinal numbers are adjectives and agree like any -o adjective: il primo piano, la prima porta. After the first ten they are built from the number plus -esimo: undicesimo, ventesimo. For floors, use al: abito al terzo piano.
Examples
- Abito al terzo piano.
- I live on the third floor.
- È la seconda porta a destra.
- It's the second door on the right.
- Il bagno è al primo piano.
- The bathroom is on the first floor.
The mistake to avoid
Italian counts floors like British English: the piano terra is the ground floor, and the primo piano is one floor up.
Where this fits in
Home & neighbourhood, Italian A1: Describe your home and its rooms, say where things are, and talk about the places near where you live.