Some original adverbs: seldom, always, yesterday, today, tomorrow, here, there, never, well.
Comparative & superlative degrees are formed by adding ‘er’ and ‘est’ to the positive degree.
When the positive (adjective) ends in ‘e’, only ‘r’ and ‘st’ are added to comparative & superlative respectively.
When positive (adjective) ends with ‘y’ and has a consonant before it - ‘y’ is changed into ‘i’ and ‘er’. and ‘est’ are added.
When adjective ends with vowel + y, ‘er’ and ‘est’ is added.
In small words - when a single consonant is at the end, we double the consonant in comparative and superlative respectively and add er and est.
IRREGULAR COMPARISON: Some adjectives do not follow any rules and they have their comparatives & superlatives.