How do you find the root of a word?

Although there is no particular rule for finding the root of a word, one way to do this is to check if the word has any affixes (suffix and/or prefix) added to it.

For example, the word “hyperactive” has the prefix “hyper-” (meaning “over”) and the suffix “-ive” (meaning “having the nature of”). If we remove the affixes, we get the root word (“act”).