Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021
Use comparatives and superlatives with care
Choose adjectives and adverbs with care
Grammar
Most adjectives and adverbs have three forms: the positive, the comparative, and the superlative.
POSITIVE |
COMPARATIVE |
SUPERLATIVE |
fast |
faster |
fastest |
careful |
more careful |
most careful |
bad |
worse |
worst |
good |
better |
best |
Comparative versus superlative
Use the comparative to compare two things, the superlative to compare three or more.
Forming comparatives and superlatives
To form comparatives and superlatives of most one- and two-syllable adjectives, use the endings -er and -est: smooth, smoother, smoothest; easy, easier, easiest. With longer adjectives, use more and most (or less and least for downward comparisons): exciting, more exciting, most exciting; helpful, less helpful, least helpful.
Some one-syllable adverbs take the endings -er and -est (fast, faster, fastest), but longer adverbs and all of those ending in -ly form the comparative and superlative with more and most (or less and least).
The comparative and superlative forms of some adjectives and adverbs are irregular: good, better, best; well, better, best; bad, worse, worst; badly, worse, worst.
Double comparatives or superlatives
Do not use double comparatives or superlatives. When you have added -er or -est to an adjective or adverb, do not also use more or most (or less or least).
Absolute concepts
Avoid expressions such as less perfect, very round, and most unique. Either something is unique or it isn’t. It is illogical to suggest that absolute concepts come in degrees.