[*]77.
The regular Nominative plural of i-stems
is -ēs,1 but -īs is
occasionally found. The regular Accusative plural -īs is common, but not exclusively used in
any word. An old form for both cases is -eis (diphthong).
1 The Indo-European ending of the
nominative plural, -ĕs
(preserved in Greek in consonant stems, as ὄρτυξ, ὄρτυγ-ες), contracts with a stem-vowel
and gives -ēs in the
Latin i-declension (cf, the Greek plural ὄεις). This -ēs was extended to consonant stems in
Latin.