An Adjective is a word joined to a Substantive to express its
Quality[15].
In English the Adjective is not varied on account of Gender, Number,
or Case. The only variation it admits of is that of the Degrees of
Comparison.
Qualities admit of _more_ and _less_, or of different degrees: and the
words that express Qualities have accordingly proper forms to express
different degrees. When a Quality is simply expressed, without any
relation to the same in a different degree, it is called the Positive;
as, _wise_, _great_. When it is expressed with augmentation, or with
reference to a less degree of the same, it is called the Comparative;
as, _wiser_, _greater_. When it is expressed as being in the highest
degree of all, it is called the Superlative; as, _wisest_, _greatest_.
So that the simple word, or Positive, becomes Comparative by adding _r_
or _er_; and Superlative by adding _st_, or _est_, to the end of it. And
the Adverbs _more_ and _most_ placed before the Adjective have the same
effect; as, _wise_, _more wise_, _most wise_[16].
Monosyllables, for the most part, are compared by _er_ and _est_; and
Dissyllables by _more_ and _most_: as, _mild_, _milder_, _mildest_;
_frugal_, _more frugal_, _most frugal_. Dissyllables ending in _y_ easily
admit of _er_ and _est_; as _happy_, _lovely_. Words of more than two
syllables hardly ever admit of _er_ and _est_.
In some few words the Superlative is formed by adding the Adverb
_most_ to the end of them: as, _nethermost_, _uttermost_, or _utmost_,
_undermost_, _uppermost_, _foremost_.
In English, as in most languages, there are some words of very common use
that are irregular in this respect: as, _good_, _better_, _best_; _bad_,
_worse_, _worst_; _little_, _less_[17], _least_; _much_, _or many_,
_more_, _most_; and a few others.