Photo courtesy of Pixaby, CCO

There are examples in the English language where important and common prefixes all mean the same, and yet are different. What makes this so confusing is that the prefixes are not interchangeable. In other words, it is easy to use the wrong one!

A prefix, as you probably know, is a letter or combination of letters which, when added to the root word, change that word’s meaning. The root word is a word without any affixes, prefixes or suffixes. Add the prefix un- to usual and you have unusual. Add im- to proper, and you get improper. Note that both prefixes created a word which is the exact opposite of the word they were added to. There are multiple examples of negative prefixes in English, creating opposites of nouns, verbs, adjectives, and adverbs.

Examples of Negative Prefixes:

• Non- Add non to the root noun sense = nonsense
• In- Add In to the root adjective conceivable = inconceivable
• Un- Add to the root adverb conditionally = unconditionally
• Im- Add to the adverb prudently = imprudently
• Ir- Add to the adjective regular = irregular
• A- Add to the adjective moral = amoral
• Dis- Add to the root verb avow = avow
• De- Add to the root verb couple = decouple
• Dis- add to the rot verb inclined = disinclined

In each case, the spelling of the root word doesn’t change. However, the root word can sometimes give you a clue as to which prefix to use.

• Words which begin with ir- and are negatives of their root always begin with r: irrespective, irreplaceable.
• Words which begin with im- and are negative always begin with either m or p: impossible, immoderate.
• Words which begin with il- and are negatives of their root always begin with l: illegible, illiterate.
• Words which begin with a- and are negatives of their roots always begin with a consonant: apolitical, atheist.
• Words which begin with non- are absolute negatives of the root word. There is no ambiguity of the word being the total opposite of its root, as there can be with un- or in-: nonconformist, nonsmoker.

You have to use caution though since some words sound correct with more than one prefix. Consider the word gracious, meaning courteous, kind, and pleasant. There is a word, ingratitude, which means to not show appreciation. However, there is no such word as ungratitude. There is also no such word as ingracious. Someone can be ungracious, though. As for nongratitude or nongracious? Nope, sorry. Those are not real words.

Next week we’ll look at some suffixes.