inflectional

This term is used almost exclusively within the specialized fields of linguistics and morphology. It describes the process of altering a word's form to express grammatical categories without changing the word's core meaning or its part of speech. For example, adding an -s to a noun to make it plural is an inflectional change.

It is frequently contrasted with derivational morphology, where adding an affix creates a new word with a different meaning or category, such as turning the verb "govern" into the noun "government." While derivational changes create new lexemes, inflectional changes merely provide the necessary grammatical markers for a sentence to be syntactically correct.