Some describing words tell how things are different.
We add er to a describing word to tell how two things are different.
The elephant is bigger than the dog.
The dog is smaller than the elephant.
The grandmother is older than Jennifer.
Jennifer is younger than her grandmother.
Yellow is brighter than purple.
Purple is darker than yellow.
Some describing words tell how more than two things are different.
We add est to a describing word to tell how more than two things are different.
The shark is the biggest.
Nemo is the smallest.
The giraffe is the tallest animal.
The alligator is the shortest animal.
The green M&M's are the longest.
The blue M&M's are the shortest.