'on' is inflected for person and number with prefixes:

Compared to derivation

Inflection is the process of adding inflectional morphemes that modify a verb's tense, mood, aspect, voice, person, or number or a noun's case, gender, or number, rarely affecting the word's meaning or class. Examples of applying inflectional morphemes to words are adding -s to the root dog to form dogs and adding -ed to wait to form waited.

In contrast, derivation

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