Use the comparative form to talk about how two things are different.
I am taller than you.
This book is thicker than that one.



1) If an adjective has one syllable, add er to the end. If it ends in e already, just addr.
tall   =>  taller     nice  =>  nicer
thick  =>  thicker    late  =>  later

2) If an adjective ends in one vowel and one consonant, write the consonant again, then write er. But never write a w twice.
big   =>  bigger     new   =>  newer (NOT newwer) thin  =>  thinner    slow  =>  slower (NOT slowwer) slim  =>  slimmer
My brother is thinner than me.

3) If an adjective has two syllables and ends in y, change the y to i and add er.
funny   =>  funnier     silly   =>  sillier 
Which of these books is funnier?

5) Some adjectives have irregular superlative forms. These are listed below.
good  =>  better
bad   =>  worse
far   =>  further


Add than after a comparative adjective to compare one thing with another. However, this is not always necessary.
My house is smaller than yours.