With nouns ending in o preceded by a consonant, the plural in many cases is spelled by adding -es (pronounced /z/):
hero heroes
potato potatoes
volcano volcanoes or volcanos
However many nouns of foreign origin, including almost all Italian loanwords, add only -s:
canto cantos
hetero heteros
photo photos
zero zeros
piano pianos
portico porticos
pro pros
quarto (paper size) quartos
kimono kimonos
维基百科是这么说的,外来词,包括拉丁词,只加s
hero heroes
potato potatoes
volcano volcanoes or volcanos
However many nouns of foreign origin, including almost all Italian loanwords, add only -s:
canto cantos
hetero heteros
photo photos
zero zeros
piano pianos
portico porticos
pro pros
quarto (paper size) quartos
kimono kimonos
维基百科是这么说的,外来词,包括拉丁词,只加s