Here are 3 ways to compare something with an adjective in a sentence:

1. If there are two things to compare, you can say one is the better OR the best. (The best is always the top.)
Between John and Paul, John is the faster runner.
OR
Between John and Paul, John is the fastest runner.
(Note: A common phrase is "Let the best man win.")

2. If there are 2 things to compare, one is better THAN the other.
John, Paul, and Martin are fast runners.
Paul is faster than Martin.
John is faster than Paul.
Thus, John is faster than Martin.
(So he is also the fastest.)

3. Sometimes the two things are exactly the same. Then we use the word AS two times:
Paul is now running faster than he did before.
He is now running AS fast AS John.

But what about poor, slow Martin?
 than slower John fastest and Paul is Martin 
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