How do I form plurals for nouns in Italian?

Plurals are formed according to the gender of the noun: normally a feminine nouns ending in a have their plural ending in e (casa-case), those ending in e have their plural ending in i (fune-funi). Masculine nouns ending in o or e have their plural ending in i. Generally, words ending with accented letters (città) have their plural with the same letter (una città-due città).