What is the plural form of equus?

The plural form of "equus," which means "horse" in Latin, is "equi." In Latin, the noun "equus" belongs to the second declension, and when it is pluralized, it typically changes the ending from "-us" to "-i." This is a standard pattern for masculine nouns of the second declension, where the nominative plural is formed by replacing the singular "-us" with "-i." Therefore, "equi" is the correct plural form.

Other options reflect variations that do not represent the correct plural form of "equus." For instance, "equa" suggests a more irregular pluralization that isn't recognized in standard Latin usage. "Equis" refers to the dative or ablative plural form and thus does not serve as the nominative plural form, while "equorum" is the genitive plural, indicating possession rather than serving in a nominative capacity. The use of "equi" accurately conveys the proper pluralization of the noun in accordance with Latin grammatical rules.