§73. Summary of i-Stems
The i-declension was confused even to the Romans themselves, nor was it stable at all periods of the language, early Latin having i-forms which afterwards disappeared. There was a tendency in nouns to lose the i-forms, in adjectives to gain them. The nominative plural (-īs)1 was most thoroughly lost, next the accusative singular (-im), next the ablative (-ī); while the genitive and accusative plural (-ium, -īs) were retained in almost all.
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.