What is the purpose of an inflectional suffix?

An inflectional suffix serves the purpose of modifying the form of a word to express different grammatical features, such as tense, mood, aspect, or number, without altering its fundamental meaning or its part of speech. For instance, by adding an inflectional suffix to a verb, such as changing "play" to "plays," one indicates grammatical tense or subject-verb agreement while keeping the meaning of the word as it refers to the same action. This ability to inflect makes it easier to fit words into the sentence structure of a language while maintaining their original category, such as a noun or verb.