XV(pt. II). I-Stem Nouns and the Ablatives (Latin in Layman's REVAMPED)

There are three important rules to remember in this chapter: (1) There are three types of third declension i-stem nouns. The first is parisyllabic in which the nominative singular (ending in - is/-es) and genitive singular have the same number of syllables. The second is monosyllabic in which the nominative singular has one syllable and two consonants at the end of its base. And the third type of i-stem includes neuter nouns with nominative singular forms ending in -e, -al, or -ar. (2) All i-stem nouns have an extra -i- in the genitive plural producing an ending -ium. Neuters also have -i in the ablative singular and -ia in the nominative and accusative plural. (3) English “with” corresponds with three uses of the ablative: the ablative of means which requires no preposition in Latin, the ablative of manner which can use cum or no preposition, and the ablative of accompaniment which uses cum always.