English adjectives and adverbs commonly distinguish three degrees: the positive (the basic form), the comparative (expressing a higher degree than is present in something else) and the superlative (expressing a maximal degree).

Comparative and superlative adjectives: formation

The comparative is formed with –er or more; the superlative is formed with –est or most. One syllable adjectives like big and fast tend to prefer –er and –est. Larger ones like beautiful and carefully take more and most.

• John is tall.
• John is taller than Peter.
• John is the tallest man I know.
• Susie drives carefully.
• Susie drives more carefully than Alice.
• Susie drives the most carefully of anybody in Paris.