Sostantivi: genere e numero

The Italian noun has two genders, feminine (f.) and masculine (m.), and two numbers, singular (s.) and plural (p.).
In the singular, masculine words typically end with the vowel -o, feminine words typically end with the vowel -a, while words ending with -e may belong to either the masculine or feminine gender.
Masculine words ending with -o in the singular end with the vowel -i in the plural, feminine words ending with -a in the singular end with the vowel -e in the plural. Words ending with -e in the singular end with the vowel -i in the plural.

The pictures below show singular and plural noun endings:

sostantivi

Noun endings:

c1 c2>

Singular		 Plural
Masculine -o -i
Feminine -a -e
Masculine or Feminine -e -i

Some examples:

c1 c2>
  Singular Plural
Masculine ragazzo - boy ragazzi - boys
Masculine libro - book libri - books
Feminine ragazza - girl ragazze - girls
Feminine penna - pen penne - pens
Masculine padre - father padri - fathers
Feminine madre - mother madri - mothers