Inglês.

Comparativos

curto: adjetivo+ER (than)

clean - cleaner

Curitiba is cleaner than SP

' terminados em CVC - dobrar a última consoante - menos terminados em W  e Y
thin - thinner

John is thinner than his brother

'terminados em y - trocar o Y por IER

happy - happier

She was happier than you

exceções 

good - better

bad - worse

far - farther, further

longo: MORE+adjetivo (than)

expensive - more expensive

SP is more expensive than Itu.

Superlativo

curto: (the) ajetivo + EST

clean - cleanest

Curitiba is the cleanest city in Brazil

' termianados em CVC - dobrar a última consoante

thin - thinnest

John is thinnest in his family

' terminados em Y - trocar Y por IEST

happy - happiest

Yesterday was the happiest day of my life

exceções:

good - the best

bad - th worts

far - the farthest/the furthest

longos - (the) most + adjetivo

New York has the most expensive holtels