Make a sentence (fast)
The plane is the fastest.
Make a sentence (sad)
The boy is the saddest.
Make a sentence (heavy)
The hammer is the heaviest object.
Make a sentence (big)
The lion is the biggest animal.
Make a sentence (tall)
The giraffe is the tallest
Make a sentence (young)
The baby is the youngest.
Make a sentence (happy)
The cat is the happiest.
Make a sentence (old)
The old lady/grandma is the oldest.
Make a sentence (slow)
The bike is the slowest.