There are three rules for forming comparative and superlative adjectives in English: 1. For one-syllable adjectives, add -er for the comparative and -est for the superlative. 2. For adjectives ending in e, add -r and -st. 3. For adjectives ending in a consonant preceded by a vowel, double the final consonant and add -er/-est.

2. You use adjectives to make comparatives, and there are several rules to
modify these adjectives to their comparative form.
One-syllable adjectives
Form the comparative and superlative forms of a one-syllable adjective
by adding for the comparative form and for the
superlative.

3. One-syllable adjectives
One-Syllable Adjective Comparative Form Superlative Form
tall taller tallest
old older oldest
long longer longest

4. One-syllable adjectives
Mike is taller than Julia.
Mary is the tallest first grader.
Jeremy is older than John.
Of the three students, Jonathan is the oldest.
My hair is longer than your hair.
Jennifer's hair is the longest hair I've ever seen.

5. If the one-syllable adjective ends with an e, just add –r for the
comparative form and –st for the superlative form.
One-Syllable Adjective Comparative Form Superlative Form
with Final -e
large larger largest
wise wiser wisest

6. It is important to remember that comparatives compare two things:

7. It is important to remember that superlatives have the quality of the adjective
to a degree greater than that of anything it is being compared to in a given context:

8. If the one-syllable adjective ends with a single consonant
with a vowel before it, double the consonant and add –er for
the comparative form; and double the consonant and add
–est for the superlative form.
Vowel before consonant
Double the consonant

9. Here are some examples:
One-Syllable Adjective
Ending with a Single Comparative Form Superlative Form
Consonant with a Single
Vowel before It
big bigger biggest
thin thinner thinnest
fat fatter fattest

10. My dog is bigger than your dog.

11. My dog is the biggest of all the dogs in the neighborhood.

12. My dog is fatter than your dog.

13. My dog is the fattest dog in the neighborhood.

14. If the two-syllable adjectives ends with –y, change the y to i and add –er
for the comparative form. For the superlative form change the y to i and
add –est.
Two-Syllable Adjective Comparative Form Superlative Form
Ending with -y
happy happier happiest
angry angrier angriest
busy busier busiest

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