What Are Affixes, Prefixes, and Suffixes in English Grammar?

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In English grammar and morphology, an affix is a word element that can be attached to a base or root to form a new word or new form of the word, usually occurring as either a prefix or suffix. Put simply, an affix is a group of letters that are generally added to the beginning or the end of a root word that can change the word's meaning.

As their names would entail, prefixes like pre-, re-, and trans- are attached to the beginnings of words such as predict, reactivate, and transaction, while suffixes like -ism, -ate, and -ish are attached to the ends of words such as socialism, eradicate, and childish. In rare cases, an affix may be added to the middle of a word and is therefore called an infix, which occurs in such words as cupsful and passersby, where the additional "-s-" affix pluralizes the words cupful and passerby, thus changing their form.

What Is a Prefix?

A prefix is a letter or group of letters attached to the beginning of a word that partly indicates its meaning, including such as examples as "anti-" to mean against, "co-" to mean with, "mis-" to mean wrong or bad, and "trans-" to mean across.

The most common prefixes in English are those that express negation like "a-" in the word asexual, "in-" in the word incapable, and "un-" in the word unhappy. These negations immediately alter the meaning of the words they are added to, but some prefixes merely change the form. The word prefix itself contains the prefix pre-, which means before, and the root word fix, which means to fasten or place. Thus, the word itself means "to place before."

Prefixes are bound morphemes, which means they can't stand alone. Generally, if a group of letters is a prefix, it can't also be a word. However, prefixation, or the process of adding a prefix to a word, is a common way of forming new words in English.

What Is a Suffix?

A suffix is a letter or group of letters added to the end of a word or root—its base form—serving to form a new word or functioning as an inflectional ending. The word suffix comes from the Latin, "to fasten underneath."

There are two primary types of suffixes in English:

  • Derivational, such as the addition of "-ly" to an adjective to form an adverb, indicating what type of word it is.
  • Inflectional, such as the addition of "-s" to a noun to form a plural telling something about the word's grammatical behavior.

Difference Between Affixes and Compound Words

Affixes are bound morphemes, which means that they can't stand alone. If a group of letters is an affix, it usually can't also be a word. However, Michael Quinion's 2002 book, "Ologies and Isms: Word Beginnings and Endings," explains the importance of these affixes to the English language and its ever-evolving usage.

Although quite similar to compounds—which combine two words with separate meanings to form a new word with a new meaning—affixes must be attached to other words in order to have meaning in and of themselves, says Quinion.

Still, affixes can often be stacked together in clusters to create complex words much more easily than compounds can, as David Crystal explains in his 2006 book, "How Language Works." He uses the example of nation, which can become national as well as nationalize, nationalization, or denationalization.


Crystal, David. "How Language Works: How Babies Babble, Words Change Meaning, and Languages Live or Die." 10/16/07 edition, Avery, November 1, 2007.

Quinion, Michael. "Ologies and Isms: A Dictionary of Word Beginnings and Endings." Oxford Quick Reference, Oxford University Press, November 17, 2005.

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Nordquist, Richard. "What Are Affixes, Prefixes, and Suffixes in English Grammar?" ThoughtCo, Aug. 27, 2020, thoughtco.com/what-is-affix-grammar-1689071. Nordquist, Richard. (2020, August 27). What Are Affixes, Prefixes, and Suffixes in English Grammar? Retrieved from https://www.thoughtco.com/what-is-affix-grammar-1689071 Nordquist, Richard. "What Are Affixes, Prefixes, and Suffixes in English Grammar?" ThoughtCo. https://www.thoughtco.com/what-is-affix-grammar-1689071 (accessed May 29, 2023).