Which grammatical function do inflectional morphemes usually serve?

Inflectional morphemes serve the important grammatical function of changing grammatical tense or number. These morphemes are affixes that attach to a word to modify its form in order to express different grammatical functions without creating a new word. For example, the addition of the inflectional morpheme "-ed" to the verb "walk" transforms it to "walked," indicating a change in tense to the past. Similarly, the addition of "-s" to the noun "cat" results in "cats," indicating a shift from singular to plural.

This role is distinct from that of derivational morphemes, which tend to create new meanings or change the part of speech of a word. Inflectional morphemes, rather, operate within the existing grammatical structure of the word to clarify its function in a sentence, such as indicating plurality, possession, tense, or comparison.