Getting back to Processes, Latin nouns come in declensions not conjugations. But there are five declensions. I was only really familiar with the first three, which were basically Fminine ending in a, masculine ending in us, and Neuter ending in um.
About.com informs me that 4th declension is ending in us, but with a u root instead. Manus, hand, is such a word. The plural posessive (genitive) is mannum instead of *manorum.
5th declension ends in es. Fides, Spes, Res are all 5th declension nouns. I can't believe I forgot that.