158. There are two forms for this inflection: the comparative,
expressing a greater degree of quality; and the superlative,
expressing the greatest degree of quality.

These are called degrees of comparison.

These are properly the only degrees, though the simple, uninflected
form is usually called the positive degree.


159. The comparative is formed by adding _-er_, and the superlative
by adding _-est_, to the simple form; as, _red_, _redder_, _reddest_;
_blue_, _bluer_, _bluest_; _easy_, _easier_, _easiest_.


[Sidenote: _Substitute for inflection in comparison._]

160. Side by side with these inflected forms are found comparative
and superlative expressions making use of the adverbs more and
most. These are often useful as alternative with the inflected
forms, but in most cases are used before adjectives that are never
inflected.

They came into use about the thirteenth century, but were not common
until a century later.


[Sidenote: _Which rule_,-- -er _and_ -est _or_ more _and_ most?]

161. The English is somewhat capricious in choosing between the