Just like nouns in Italian, adjectives have gender specific endings. The endings change depending on the noun that follows. For example:
il bambino bravo becomes i bambini bravi (the brave child → the brave children)
la bambina brava becomes le bambine brave
Adjectives can go either before or after a noun, though if the adjective is longer it goes after the noun.
Certain adjectives follow special rules:
Bello (beautiful) and Quello (that)
These two adjectives are put before the noun, and follow the rules of the definite article in Italian.
However, if bello is placed after the noun, it acts like other -a and -o adjectives.
Buono (good)
Unlike bello and quello, buono follows the rules of the indefinite article in Italian.
But if buono is placed after the noun, it too acts like other -a and -o adjectives.
In Italian, possessive adjectives and possessive pronouns take the same form. For each gender, there are six singular and six plural forms. Let's go over masculine possessives first:
Singular
1st person singular → mio
2nd person singular → tuo
3rd person singular → suo
1st person plural → nostro
2nd person plural → vostro
3rd person plural → loro
Plural
1st person singular → miei
2nd person singular → tuoi
3rd person singular → suoi
1st person plural → nostri
2nd person plural → vostri
3rd person plural → loro
Notice that when the singular possessives become plural, they follow the same ending patterns as masculine nouns, except for mio/miei and loro/loro. Let's now go over the feminine possessives:
Singular
1st person singular → mia
2nd person singular → tua
3rd person singular → sua
1st person plural → nostra
2nd person plural → vostra
3rd person plural → loro
Plural
1st person singular → mie
2nd person singular → tue
3rd person singular → sue
1st person plural → nostre
2nd person plural → vostre
3rd person plural → loro
In both the masculine and feminine possessives, loro does not change. To see if it is masculine or feminine, or singular or plural, look at the article or ending of the accompanying noun.