Comparativos Y Superlativos En Inglés

A - Comparison with -er/-est
clean - cleaner - (the) cleanest
We use -er/-est with the following adjectives:
1) adjectives with one syllable
clean | cleaner | cleanest |
new | newer | newest |cheap | cheaper | cheapest |
2) adjectives with two syllables and the following endings:
2 - 1) adjectives with two syllables, ending in -y
dirty | dirtier | dirtiest |
easy | easier |easiest |
happy | happier | happiest |
pretty | prettier | prettiest |
2 - 2) adjectives with two syllables, ending in -er
clever | cleverer | cleverest |
2 - 3) adjectives with two syllables,ending in -le
simple | simpler | simplest |
2 - 4) adjectives with two syllables, ending in -ow
narrow | narrower | narrowest |

Spelling of the adjectives using the endings -er/-est
large |larger | largest | leave out the silent -e |
big | bigger | biggest | Double the consonant after short vowel |
sad | sadder | saddest | |
dirty | dirtier | dirtiest | Change -y to -i (consonantbefore -y) |
shy | shyer | shyest | Here -y is not changed to -i.
(although consonant before -y) |

B - Comparison with more - most
difficult - more difficult - (the) most difficult
all adjectiveswith more than one syllable (except some adjectives with two syllables - see 
2 - 1 to 2 - 4)

C - Irregular adjectives
good | better | best |   |
bad | worse | worst |   |
much | more | most| uncountable nouns |
many | more | most | countable nouns |
little | less | least |   |
little | smaller | smallest |   |

D - Special adjectives
Some ajdectives have two possible forms ofcomparison.
common | commoner / more common | commonest / most common |
likely | likelier / more likely | likeliest / most likely |
pleasant | pleasanter / more pleasant | pleasantest / mostpleasant |
polite | politer / more polite | politest / most polite |
simple | simpler / more simple | simplest / most simple |
stupid | stupider / more stupid | stupidest / most stupid |
subtle...