Translation:Many cities are in America.
With macrons (cf. Wiktionary):
Multae urbēs sunt in America.
Why multae insted of multi?
Urbes is a feminine plural noun so the adjective also has to be feminine plural.
(Multi - masc. pl, multae - fem. pl, multa - neuter plural).
I could have sworn I heard "urbae"
The pronunciation of the ending of urbes is very unclear.