To form the comparative, we add "più":

freddo - cold

più freddo - colder

We form the superlative in two ways:

The so called relative superlative is formed by preceding the form of comparative with the definite article il / la / i / le:

il più freddo - the coldest

la più fredda - the coldest

i più freddi - the coldest

le più fredde - the coldest

Whereas the so called absolute superlative is formed by adding the ending –issimo (in the female gender –issima):

altissimo - very high

We do not use this form for comparisons, it generally expresses more or less what the English word "very" expresses.

Several adjectives have irregular forms: