There are three different types of comparative structures in English: INFERIORITY, EQUALITY AND SUPERIORITY
1) INFERIORITY COMPARATIVE:
Structure: [less + than] ///// [not as .......as]
Example: He is less intelligent than you
Example: He is not as intelligent as you
NOTE: "Less" is usually used fot uncountables and "fewer" for countables.
2) EQUALITY COMPARATIVE:
Structure: [as + as]
Example: He is as intelligent as you
3) SUPERIORITY COMPARATIVE
This type of comparative has two different structures depending on the lenght of the adjective:
SHORT ADJECTIVES [-er + than]
Example: He is taller than me
LONG ADJECTIVES [more + than]
Example: He is more intelligent than me
Pretty - Prettier (The "y" is substituted by "i", and after that we add "-er".
Large - Larger (We add just one "r" because the adjective finishes in "-e".
Big - Bigger (If an adjective finishes in consonat+vowel+consonant, the last consonant is doubled and "-er" is added).
IRREGULAR ADJECTIVES IN COMPARATIVE
Good - Better
Bad - Worse
Far - Further
In English, the superlative also has two different structures depending on the adjective length:
Structure: [the + -est]
Example: He is the tallest boy in the classroom
Structure: [ the most + adjetivo]
Example: He is the most intelligent boy in the classroom
IRREGULAR ADJECTIVES IN SUPERLATIVE
Good - The best
Bad - The worst
Far - The furthest