Theorie:

The comparative form of an adjective is used for comparing two people or things (e.g., he is taller than me), while the superlative is used for comparing one person or thing with every other member of their group (e.g., he was the tallest boy in the class).
Regular adjectives with one syllable
Adjective
Comparative
Superlative
tall
taller
the tallest
large
larger
the largest
big
bigger
the biggest
 
 
 
 
 
 
 
 
tall-taller-tallest.jpg
tall - taller - the tallest
 
1. Adjectives ending in two constants or two vowels and a constant , add -est.
 
long - longer - the longest, short - shorter - the shortest, bright - brighter - the brightest/

2. Adjectives ending in -e, add -st.
 
Nice - nicer - the nicest, late - later - the latest, safe - safer - the safest.
 
3. Many adjectives ending in a single vowel + single consonant double the consonant and, add -est.
 
Fat - fatter - the fattest, thin - thinner - the thinnest, flat - flatter - the flattest.
Regular adjectives with two or more syllables
Adjective
Comparative
Superlative
heavy
heavier
the heaviest
modern
more modern
the most modern
important
more important
the most important
common
more common
the most common

 
 
 
 
 
 
 
 
 
1. Adjectives ending in -y change y to i and add -est.
 
Happy - happier - the happiest, dirty - dirtier - the dirtiest, funny - funnier - the funniest.
 
2. For most longer adjectives use more and the most.
 
More comfortable, most independent.
 
3. Some two-syllable adjectives can form their comparatives and superlatives in two ways: by adding -est or with more and most.
 
More clever/ most clever, more pleasant/ most pleasant. 
Irregular adjectives
Adjective
Comparative
Superlative
good
better
the best
bad
worse
the worst
old
older
the oldest
 
elder
the eldest
far
farther
the farthest
 
further
the furthest
 
  
  
  
  
  
  
  
  
  
 
Comparative and superlative adjectives in context
- More/-er + than
 
I'm taller than my brother.
My brother's more serious than me.
I'm more intelligent than he is/him.
 
- The most/-est
 
I'm the tallest.
My sister's the most intelligent student in her school.
 
- Less + than/ the least
 
That film was less interesting than the last one I saw.
It was the least interesting film I've seen all year.
Other comparative constructions
- as...as
 
This construction can be used with adjectives or adverbs to make comparisons between two things or people.
 
I'm as tall as my brother.
Trains don't travel as fast as planes.
 
In negative sentences so can be used instead of the first as.
 
Cats aren't so friendly as dogs.