Select Page

If you ask people what words are made of, you’ll likely get a variety of answers. Words are made up of a sequence of letters, like C-A-T. Someone else may say that words consist of a sequence of sounds, like “kay,” “ay,” and “tee.” Others may give you the definition of a word. From a structural perspective, words are made up of morphemes.

What is a morpheme? A morpheme is the smallest unit of a word that carries meaning or performs a grammatical function. They are the building blocks of words.

There are many ways to examine language. By looking at language from different perspectives, we gain awareness and appreciation for the resources available to us as language learners and users. Words are the basis for conveying meaning in all the languages of the world. We’ll begin by providing a quick overview of the types of morphemes and the jobs they perform in English.

Free Morphemes

Free morphemes are the smallest units of words that can stand alone as words. The word “a” consists of a single free morpheme “a.” However, this does not mean that all free morphemes consist of one syllable. There are many free morphemes that have more than one syllable, like “happy” and “elegant.”

Many words are formed by combining free morphemes in a process called compounding. For example, the morphemes “dog” and “house” can be combined to form “doghouse,” whose meaning can be paraphrased as “a house for a dog.” In each case, the meanings associated with the free morphemes are integrated into the meaning of the resulting compound. However, there are words that look like, at first glance, compound words.

How many morphemes are in the word “father”?

“One.” There appears to be two words—“fat” and “her”—within “father.” However, think about this, does the meaning of the word “father” stem from combining the meanings of the morphemes “fat” and “her”?

Bound Morphemes

In contrast to free morphemes, bound morphemes are the opposite: they cannot stand alone as words. There are several subcategories of bound morphemes: derivational morphemes, inflectional morphemes, and bound stems

Derivational Morphemes

As bound morphemes, derivational morphemes cannot stand alone as words. New words are derived when they are added to another word. When they are added, they add meaning or perform a function. In English, derivational morphemes are recognizable as prefixes and suffixes.

In English, derivational morphemes have two primary functions:

  • Derivational morphemes can change the underlying meaning of a word, but not its lexical category.
  • Derivational morphemes can change the lexical category of a word, but not its underlying meaning.

Change the Meaning of a Word

The function of changing the underlying meaning of a word, but not its lexical category is typically associated with prefixes in English.

un- + fit → unfit or “not fit”

re- + mind → rewrite or “do over the action mind”

pre- + write → prewrite or “do something prior to the action write”

In each example above, the meaning of the resulting word is different from the word that had the prefix added to it. However, the lexical category, or part of speech, did not change. “Fit” and “unfit” are both adjectives. “Mind” and “remind” are verbs as are “write” and “prewrite.”

Change the Lexical Category of a Word

In contrast, the function of changing the lexical category of a word, but not its underlying meaning is usually associated with suffixes in English.

govern(v) + -ment → government(n)

ease(v) +-y → easy(a) +=ly → easily(adv)

beaufy(n) +-ful → beautiful(a) + -ly → beautifully(adv)

The addition of a suffix in each example above created a new word in a different lexical category that retained the meaning of the original word. For example, the word “government” can be defined as an institution that performs the action “govern.”

Exceptions to the Rule?

There are also examples of derivational morphemes that seem to violate these functions. For example, the words “hasten” and “chasten” would appear to be similar.

haste(a) + -en → hasten(v)

chaste(a) + -en → chasten(v)

It appears that this pair of derivations reflect the second function: derivational morphemes can change the lexical category of a word, but not its underlying meaning of a word. “Hasten” could be paraphrase as to do something hurriedly or in haste. However, “chasten” doesn’t appear to have anything to do with being “chaste.” Is this a violation of the second function?

Lexico defines “chaste” as “not having any sexual nature or intention” and “without unnecessary ornamentation; simple or restrained.” It defines “chasten” as “(of a rebuke or misfortune) have a restraining or moderating effect on.” Looking for common ground, we see that both definitions share the concept of restraint; so, an argument could be made that “chaste” and “chasten” share a common meaning and that the addition of the suffix allows that concept to be employed as an adjective and as a verb. The perceived difference in meaning may arise from differences in how these words are use and in their contexts.

Fixed Forms

Besides these two functions, derivational morphemes have another defining characteristic: they have fixed forms. This means that they are added “as is” to a word. This may cause the spelling of the underlying word to change. For example, the “e” in “ease” disappears when the suffix “-y” is added to form “easy.” In another example, the “y” in “beauty” is replaced with an “i” when the suffix “-ful” is added to create “beautiful.”

Inflectional Morphemes

n contrast to derivational morphemes, inflectional morphemes carry grammatical information and they do not have fixed forms.

What do the following words have in common?

cats peaches children oxen mice cacti

They are all plural forms of nouns. What tells you that these are plural forms? The “-s” in “cats,” the “-es” in “peaches,” the “-ren” in “children and so forth. All of these words are plural forms of nouns, but they do not signal the plural in the same way.

Now, another question. Which word is different from the rest? 


The other five words have something added or changed to the end of the underlying singular noun. But, in the case of “mice,” the underlying singular form is “mouse.” Nothing has been added or changed to the end of that word. Something else happened to the word. (If you know what happened, please answer in a comment below. Otherwise, this will be the topic of another article.)

Similar behavior occurs with the past tense forms of verbs and the comparative and superlative forms of adjectives. Grammatical information is added, but they are expressed in different ways.

Bound Stems

Derivational and inflectional morphemes make up the majority of bound morphemes in English, but bound stems are another type of bound morpheme. Most words in English have a free morpheme as its starting point, but there are some words that seem to have starting points that are not free morphemes. Some words seem to begin with prefixes, but if they are removed, what remains cannot stand alone as a word. Here are some examples.

result, consult, insult

receive, conceive, deceive

“-sult” and “-ceive” are examples of bound stems. SIL (Summer Institute for Linguistics) defines a bound stem as “a stem which cannot occur as a separate word apart from any other morpheme.” 

Related Questions

Are there any other types of morphemes in English? There are the so-called “cranberry morphemes” that are idiosyncratic in usage and do not carry meaning or perform a function. However, they can be used to distinguish words. The “cran-“ in “cranberry” is an example.

How can morphemes help learning a language? Morphemes are the building blocks of words; so, understanding what they do and how they are organized in a language can aid tremendously in developing one’s vocabulary.

If you have any questions about morphemes, leave a comment in the form below.