In general, in Genoese the -s- between vowels is pronounced as voiced s, -[z]-, in accordance with etymology and with the convention adopted in all Romance languages that possess this sound, as in reusa [ˈrøːza] (Italian, Catalan and Portuguese “rosa”, French “rose”), casa [ˈkaːza] (Italian, Catalan and Portuguese “casa”) and sposâ [spuˈzaː] (Italian “sposare”, Catalan “esposar”, French “épouser”). For certain words, chiefly owing to the lack of definitive standardisation in the writing of Genoese, contrasting spellings have historically spread and still coexist in which this sound is represented by -z-, as in zeneize [zeˈnejze] “Genoese”, creuza [ˈkrøːza] “narrow lane between two walls” and cazann-a/cazaña [kaˈzaŋˑa] “customer”. In this dictionary, in accordance with the rules of written Genoese adopted in many other contexts, such terms are spelled according to the parameters of the general rule stated above (i.e. zeneise, creusa, casaña). Spellings of the type zeneize, moreover, would also justify eccentric forms such as caza [ˈkaːza] “house” or nazo [ˈnaːzu] “nose”, which must instead be written casa, naso. Before a long vowel marked with a colon, however, the -s- is pronounced voiceless, -[s]-, as in Italian sole: cäsiggion [kaːsiˈdʒuŋ] “mushroom stem”, cösa [ˈkɔːsa] “thing”, fäso [ˈfaːsu] “false, fake”, pösâ [pɔˈsaː] “to lay, to place”. The only exceptions requiring the spelling -z- are once again dictated by etymology: mezo [ˈmeːzu] “half” < medju(m), caize [ˈkajze] “mist” < *calige(m), strazzetto [straˈzetˑu] “suburban lane” < ex trajectu(m).

Terms in -eise form the plural in -eixi: zeneise “Genoese” > zeneixi. Terms in -aise form the plural in -aixi: paise “country” > paixi. Terms in -ase and those in -aso form the plural in -axi: ase “donkey” > axi; naso “nose” > naxi.