You can use comparatives to compare between two people. You have to add the word than in case of Comparatives.
Examples: Ali is smarter than Tom. Mike is nicer than his brother. Sara is more intelligent than her sister.
You can use the superlatives if you want to compare one person with two or more people. Tom is the richest among his friends. He is the fastest one. Aisha is the most interesting girl in my class. Burj Khalifa is the tallest tower in the world.
There are some irregular words that you have to memorize. Good better best Bad worse worst little less least much more most far further furthest
Examples: This teacher is better than the one we had last year. Harry is the best cook.