Comparative are a type of adjectives used for highlighting the difference between two objects, or two nouns. They are used in the comparison of two objects, or two nouns.
The following is a sentence that uses a comparative : My female cat is younger than that cat. In this sentence, the word “younger” is the comparative .We can do another example: My apple is redder than your apple. In this sentence, the word “redder” is the comparative.
A trick for spotting comparative adjectives is looking for the word “than” in sentences. A comparative adjective is usually used before “than” if a comparative is used. Additionally, comparative frequently have the ending “er.”
Adjectives of just one syllable form the comparative by adding "-er":
- Bright...brighter
- Clear...clearer
- Fast...faster
If a one syllable adjective ends in "e", simply add "r":
- Nice...nicer
- Fine...finer
For some adjectives, it is necessary to double the last letter before adding "-er". (For spelling: doubling letters, see next week's grammar question).
All adjectives of three or more syllables form the comparative with "more ".
- Beautiful... more beautiful
- Comfortable...more comfortable
Adjectives of two syllables are more complicated. To see which is the usual form you should see your dictionary. Most adjectives of two syllables form the comparative with "more":
- Famous... more famous
- Thank...more thankful
However, some adjectives of two syllables form the comparative with "-er":
Those that end in "y", change the "y" to "i" and add "-er":
- Happy...happier
- Funny...funnier
Those ending in a vowel-sound that is not stressed:
- Yellow... yellower
- Simple... simpler
In addition, there are some (common) irregular comparative adjectives:
- Good …better
- Bad …worse
- Much … more
http://www.britishcouncil.org/learnenglish-central-grammar-comparative-adjectives.htm
Superlative Adjectives
The superlative is used to say what thing or person has the most of a particular quality within a group or of its kind. Superlative adjectives normally come before any other adjectives.