How are base words modified?

Base words can be modified in a range of ways through the use of affixes.

Affixes (i.e., prefixes and suffixes) serve a wide variety of functions in English, including to create nouns, verbs, adjectives, and adverbs or to mark tenses, number, and so on.

Common prefixes include “pre-,” “un-,” “dis-,” “anti-,” and “hyper-.” Common suffixes include “-sion”/“-tion,” “-ness,” “-ful,” and “-ly.”