Question about Second Declension Plural Dative
Latin: I'm working in the second declension right now, and trying to get it down. When I decline a noun into the plural dative, do I maintain the final vowel of the base?
For example, I'll use the nominative "Gladius." It's a 2nd declension noun. The root base is, I presume, "Gladi-". If correct, do I maintain the i there at the end when putting the word into the plural dative (-is)? It would look, to illustrate, like this: "Gladiis."
Or another, nominative "Nubius," to plural dative "Nubiis"?
Thanks!