What are inflectional morphemes?

Languages that have inflectional grammar are those that use ending systems to reflect gender, case, and/or number, among other things. Inflections are different than agglutinative affixes in that inflectional patterns vary depending on the inflectional category a Word is in. Thus, Latin masculine o-stem nouns take -us and -um in the nominative and accusative case, but Latin u-stem nouns take -us and -us in those two cases.