§77. Summary of i-Stems
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).
J. H. Allen and J. B. Greenough, New Latin Grammar (Boston: Ginn, 1903). Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities.