LINGVA LATINA
 
  We use comparative and superlative forms to compare things and to describe quantity of their quality. In English language, we add some suffixes, or additional words to the adjectives to make comparison.
For example: I am taller than you.
She is the tallest in my classroom.
It is more beautiful than the other.
This subject is the most complicated one in my book.
  There are similar ways to create comparative and superlative forms in Latin.
 Positive Degree (Gradus positivus)
 It is the natural form of adjectives. In positive degree, adjectives are not comparative, nor superlative.
 bonus -a -um (good)
 brevis -e (little)

 
 Comparative Degree (Gradus comparativus)

 This degree is used to compare two things by using the same quality. First things first is to remove the genitive endings of a Latin adjectives to form the comparative degree. After removing the ending, you will have the base of the adjective.
 trīstis (sad) trīst-is = trīst - the base
 Second step is to add -ior for masculine and feminine, and -ius for the neuter to the base.
 formula; base + ior = comparative form (masculine and feminine)
                base + ius = comparative form (neuter)

 
 examples;
trīst + ior = trīstior (m./f.)
                   trīst + ius = trīstius (n.)

 
The comparative forms are decline like the third declension of adjectives.
  However, there are some differences:
  • The ablative, singular ending is -e, not .
  • The neuter, accusative, plural ending is -a, not -ia.
  •  The genitive, plural ending is -um, not -ium.
 Too see the third declension of adjectives click!!!
Important note: Unlike in English, the comparative can mean 'rather', 'quite', or 'too' in Latin. For example; 'longior' can mean 'too long', 'quite long' or 'rather long'.
  Superlative Degree ( Gradus superlativus)
 This degree is used to express the highest quality of a thing. To create superlative degree, again, remove the genitive ending. There are three suffixes  to add to the base. The most common suffix is -issim-. The others are -errim- , and -lim-.
 formula: base + issim + us(mas.)/a(fem.)/um(neu.) = superlative form

 example: long + issim + us/a/um = longissimus -a, -um

 All adjectives endings in -er ( e. g. pulcher, celere, sacer...) will have -errim- to form superlative.
 formula: base + errim + us(mas.)/a(fem.)/um(neu.) = superlative form

 example: pulch + errim + us/a/um = pulcherrimus -a, -um


 A few words end in -lis (facilis, difficilis, gracilis, similis, dissimilis, gracilis, humilis). These ones will have -lim- as the suffix to the base to form superlative.
 formula: base + lim + us(mas.)/a(fem.)/um(neu.) = superlative form

 example: dissimil + lim + us/a/um = dissimillimus -a, -um

 Important note: If a superlative is followed by 'quam', the meaning will be 'as...possible'. For example, 'quam humillimus' means 'as low as possible'.
 Periphrastic Degrees
 Adjectives whose stems end on a vowel(e.g. arduus, pius...) get magis (more) to form comparative, and maxime (most) to form superlative.
 arduus, -a, -um (steep)
 comparative: magis arduus, -a, -um  superlative:  maxime arduus, -a, -um
 
Iregular adjectivesThere are some irregular adjectives. Some common ones are:
  Positive                  Comparative                Superlative
  bonus (good)              melior                            optimus
  malus (bad)                peior                              pessimus
  magnus (great)          maior                             maximus
  multus (much)           plūs                               plūrimus
  paruus (small)            minor                            minimus
  exterus (external)       exterior                          extremus
  īnferus (below)          inferior                           infimus