Comparatives

1. Comparative forms

There are two main forms of comparative and superlative adjectives in English: one-word forms (“taller”, “tallest”) and two-word forms (“more effective”, “most effective”). Here are some rules.

2. One-syllable adjectives

• One-syllable adjectives usually form one-word comparatives ending in -er, and superlatives in -est:

fast - faster, fastest

• Participial adjectives with the ending -ed form comparatives with “more” and superlatives with “most”:

stressed - more stressed, most stressed

• The following common adjectives are irregular:
  

good - better, best
bad - worse, worst
far - farther/further, farthest/furthest

3. Two-syllable adjectives

• Two-syllable adjectives ending in -y have comparatives ending in -ier, and superlatives ending in -iest:

costly - costlier, costliest
busy - busier, busiest

• Two-syllable adjectives ending in -ing, -ed, -ful and -less take “more” and “most”:

daring - more daring, most daring
grateful - more grateful, most grateful
thankless - more thankless, most thankless

• Some two-syllable adjectives can take both forms, although the use of “more” and “most” is preferred:

polite - politer/more polite, politest/most polite
common - commoner/more common, commonest/most common

Most other two-syllable adjectives take “more” and “most”. Learners’ dictionaries list the correct form.