In English superlatives are formed by adding the suffix –est (if they have one syllable) or with the construction the+most+positive form (if they have two or more syllables). The comparison is preceded by the preposition  in/of (or between/among). Note that the comparison can also be expressed by a relative clause (He’s the smartest guy that I’ve ever met).

Adjective Rule Examples
If the adjective is short (one syllable) The superlative is formed by adding the definite article the before the positive form and  the suffix – est to the adjective

 
  • the short + est in/of (il più corto di)
  • the long + est in/of (più lungo di)
  • the large + st in/of (il più largo di)
  • the wide + st in/of (il più ampio di)
  One syllable adjectives ending with a single consonant usually double it
  • the big+g+est in/of (il più grande di)
  • the fat+t+est in/of (più grasso di)
If the adjective is long (two or more syllables) The superlative  is formed by putting the most before the adjective
  • the most + beautiful (il più bello)
  • the most + interesting (il più interessante)
  • the most + enjoyable (il più divertente)
A number of adjectives of two syllables follow one rule or the other Adjectives of two syllables ending with –er, -y or -ly add –er (-y changes in –i)
  • the clever +est (più intelligente di)
  • the earli + est (al più presto)
  • the holi+est (il più santo)
  Adjectives of two syllables ending with –ful, or –re usually add more
  • the most + watchful (più vigile)
  • the most + obscure (più oscuro)

Construction at a glance

Form Construction Examples
Majority Superlative    
One syllable The +positive form + est…in/of
  • He’s the smartest guy in his class
two or more syllable The + most + positive form ….in/of
  • She’s the most beautiful girl in her class
Minority Superlative    
All adjectives The + least + positive form ….in/of
  • He’s the least clever guy in his class
Absolute Superlative    
All adjectives Absolute superlatives are formed by putting words such as very, extremely, absolutely, really and so on.
  • She’s extremely careful about her husband’s diet.

 

Adjectives -Superlative