Adjectives modify a noun, or in other words,  they provide more information about/ describe a noun.  In Italian, adjectives must agree in number and gender with the noun they modify.

There are two groups of adjectives:

• Adjectives ending in -o  (in masculine form)
• Adjectives ending in -e 

Adjectives that end in -o have four forms (masculine, feminine, singular, plural):
                      [masculine]                                          [feminine]  
      Ex:        Il vestito rosso  (the red dress)       La gonna rossa   (the red skirt)
                    I vestiti rossi     (the red dresses)    Le gonne rosse   (the red skirts)

Adjectives that end in -e have only singular and plural forms:
       Ex:       Il tavolo grande                                L'aula grande        
                    Gli edifici grandi                               Le fontane grandi

Here are some common adjectives:

alto                               tall
grande                        big; great
lungo                           long
largo                            wide
pieno                           full
vecchio                       old
anziano                       elderly
grasso                         fat
bello                             beautiful/handsome
bravo                           good at sth. / well-behaved
buono                          good / kind
caro / costoso          expensive
caldo                            hot
divertente                   fun / enjoyable
facile                            easy

basso                          short
piccolo                        small
corto                            short
stretto                         narrow / tight
vuoto                           empty
nuovo                          new
giovane                       young
magro                          thin
brutto                           ugly
cattivo                         bad /naughty
​[cattivo]                       bad / negative
economico                 cheap (price)
freddo                          cold
noioso                          boring
difficile                         difficult

ATTENZIONE
* When an adjective modifies two nouns of different gender, it retains the masculine ending:
      Ex:  I ragazzi e le ragazze italiani     (the Italian boys and girls)

​* The colours rosa, viola, and blu are invariable - they do not change:
      Ex:  Il maglione rosa            (the pink sweater)            La gonna rosa         (the pink skirt)
              Gli stivali blu                   (the blue boots)                Le borse blu               (the blue purses)

You may have noticed from the examples above that in Italian, unlike English, adjectives typically follow the noun they modify; however, adjectives can also precede the noun they modify. Adjectives that follow a noun are stronger or more emphatic than adjectives that precede a noun.

​It is important to note that some adjectives, such as grande, bello, alto, nuovo, vecchio, buono, diverso, povero, caro... actually change their meaning depending on their placement:
​
      Ex:    Un grande palazzo     a grand/great palace
                Un palazzo grande     a big palace

                Un vecchio amico     an old friend (one you've known for a long time)
                Un amico vecchio     a friend who is old in age

                Un povero uomo     a poor man (miserable; despairing)
                Un uomo povero     a poor man (one who lacks money)         

Pratica!