+--------+---------------------+---------------------------------+
| Example| M. ācer, F. ācris, Ne. ācre, _sharp_ |
| Stem | ācri-. |
+--------+---------------------+---------------------------------+
| | Singular. | Plural. |
| +---------------------+---------------------------------+
| | MASC. FEM. NEUT. | MASC. FEM. NEUT. |
| _Nom._ | ācer ācris ācre | ācres ācres ācria |
| _Gen._ | ācris ācris ācris | ācrium ācrium ācrium |
| _Dat._ | ācrī ācrī ācrī | ācribus ācribus ācribus |
| _Acc._ | ācrem ācrem ācre | ācrīs, -ēs acrīs, -ēs ācria |
| _Abl._ | ācrī ācrī ācrī | ācribus ācribus ācribus |
+--------+---------------------+---------------------------------+
629. In all cases but the masculine nominative singular these adjectives
are just like those in #-i-# ‘of two endings’ (630). But the ablative
always has #-ī#, never #-e#, and the genitive plural always has #-ium#,
never #-um#. In #celer# the second #e# belongs to the stem: M. #celer#,
F. #celeris#, Ne. #celere#; the genitive plural, which is #celerum#, is
found only as a substantive. Most of these adjectives have now and then
a masculine in #-is#, like adjectives ‘of two endings’ (630), and in old
Latin the nominative #-er# is rarely feminine.