There are three degrees of Adjectives in Latin: Positive, Comparitive, and Superlative.

For Example:
Positive - Good, Bad, Indifferent
Comparative - Better, Worse, more Indifferent
Superlative - Best, Worst, most Indifferent

Adjectives are almost always in one of the first three declensions, and those in the first two are formed the same way:

  • To form the positive, take the base (the word without the ending given), and add the endings corresponding to it's declension (for example, first declension adjectives would add -us for masculine, -a for feminine, or -um for neuter.)
  • To form the comparitive, take the base and add -ior for masculine or feminine, or add -ius for neuter
  • To form the superlative, take the base and add -issimus for masculine, -issima for feminine, and -issimum for neuter.
For Example:
     mas         fem        neu
pos  altus       alta       altum       (high)
com  altior      altior     altium      (higher)
sup  altissimus  altissima  altissimum  (highest)

pos  fortis      fortis     forte       (strong}
com  fortior     fortior    fortium     (stronger)
sup  fortissimus fortissima fortissimum (strongest)