I booked a single room.
SIN-go-la — stress on the first syllable. The 'g' before 'o' is hard, like in 'go'.
Use this to specify your room type at check-in, or when there is a mix-up about what type of room you reserved.
'Ho prenotato' is the passato prossimo (present perfect) of 'prenotare' (to book/reserve). Italian room types: singola (single), doppia (double with two beds), matrimoniale (double with one bed), tripla (triple), suite.
Ho prenotato una camera matrimoniale.
I booked a double room (with one bed).
Always specify matrimoniale if you want one bed, not two
Ho prenotato una camera doppia.
I booked a twin room.
A 'doppia' has two separate beds — important distinction for couples
Ho prenotato una suite.
I booked a suite.
Pronounced 'sweet' even in Italian
In Italy the 'primo piano' (first floor) is what Americans call the second floor. The ground floor is 'piano terra' or 'pianterreno'. Always clarify which floor your room is on to avoid confusion.