The Allen and Greenough is still under construction;
so some links may not work quite the way you would expect.
DECLENSION OF NOUNS
36. Declension is rpoduced by adding terminations
originally significant to different forms of stems, vowel or consonant.
The various phonetic corruptions in the language have given rise to the
several declentions. Most of the case-endings, as given in Latin, contain
also the final letter of the stem.
Adjectives are, in general, declined like nouns, and are
etymologically to be classed with them; but they have several
peculiarities of inflection (see §109 ff.).