What are the rules for the comparison of English adjectives?

In general, the English comparison of adjectives differentiates between three different forms or degrees, which are:

1. the positive (which merely represents the characteristic of something),
2. the comparative (which shows something greater),
3. and the superlative (which stands for the greatest).

By using these forms, it is possible to compare different things or different persons with each other, which means expressing inequality. Another type of comparison can be done with ‘as … as’ or ‘more/less … than’, which shows equality.

• Example sentences showing not compared and compared adjectives:
  • “Peter’s bike is small, but mine is smaller.”
    • The first adjective (small) is in the positive and the second one (smaller) in the comparative.
  • “We all have small bikes, but Tom’s is the smallest.”
    • positive (small) and superlative (smallest)
  • “Sorry, this is more important. I have to do it now.”
    • comparative
  • “That is the most difficult task I have ever done.”
    • superlative

How are the different degrees of adjectives formed?

Moreover, adjectives follow specific rules when compared. That means that their compared forms either end in ‘-er/-est’, or they are preceded by the additional word ‘more/most’. However, concerning their spelling, some details must be considered. In particular, the two forms appear as follows; there are basically two types:

1. The group of adjectives that end in ‘-er’ in their comparative and ‘-est’ in their superlative forms covers the monosyllabic and most of the disyllabic adjectives. In detail:
   • Monosyllables always get the ending or suffix ‘-er’ or ‘-est’ appended. If an adjective already ends in ‘-e’, the suffix is extended to ‘-er’ or ‘-est’ accordingly:
     • warm → warmer → warmest
     • clean → cleaner → cleanest
     • large → larger → largest
       • Careful: The ‘-e’ is already present; then only ‘-r’ or ‘-st’ is added.
     • wide → wider → widest
       • This adjective also ends in ‘-e’; the same rule applies.
     • big → bigger → biggest
       • Careful: In case the adjective ends in a short stressed vowel (here ‘i’) followed by a consonant (here ‘g’), this consonant is doubled.
     • hot → hotter → hottest
       • The doubling occurs here too (‘t’ becomes ‘tt’).
   • Adjectives that have two syllables and end in ‘-er, -y, -ow’, or ‘-le’ are also suffixed with ‘-er’ or ‘-est’, or they are extended to them accordingly:
     • clever → cleverer → cleverest
       • Merely ‘-er’ and ‘-est’ are appended.
     • funny → funnier → funniest
       • Careful: If the adjective ends in ‘-y’, it is replaced by ‘-i’.
     • easy → easier → easiest
       • The replacement of ‘-y’ happens here too.
     • shallow → shallower → shallowest
     • subtle → subtler → subtlest
       • Careful: In this case, the ‘-e’ is already there and so only ‘-r’ or ‘-st’ is appended.
2. For all other disyllables as well as tri- and polysyllables, the adverbs ‘more’ for the comparative and ‘most’ for the superlative are required. They are placed before the corresponding adjective. The adjectives themselves are not changed (inflected) in this type of comparison.
   • Examples that follow this rule of comparison:
     • boring → more boring → most boring
     • famous → more famous → most famous
     • expensive → more expensive → most expensive
     • interesting → more interesting → most interesting
     • complicated → more complicated → most complicated
     • sensitive → more sensitive → most sensitive
3. Note: The rules for comparison listed above also include some exceptions. These exceptions describe special adjectives that possess particular forms with possibly different meanings in their compared forms.

Further explanations related to the ‘Comparison of adjectives’

The following explanations relate to the topic ‘Rules for comparing adjectives in English grammar’ and might also be interesting:

• Syllables and hyphenation in English
• Exercise 1: comparison of adjectives
• Exercise 3: comparison of adjectives (elder, farther)
• Exercise 4: comparison of adjectives (late, latest, near, next)
• Exercise 1: use of adverbs and adjectives