Derivational Morpheme in Grammar

Glossary of Grammatical and Rhetorical Terms

Merge sign - Derivational morpheme
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In morphology, a derivational morpheme is an affix that's added to a word to create a new word or a new form of a word. Compare with inflectional morpheme.

Derivational morphemes can change the grammatical category (or part of speech) of a word. For example, adding -ful to beauty changes the word from a noun to an adjective (beautiful), while adding -(e)r to merge changes the word from a verb to a noun (merger). The form that results from the addition of a derivational morpheme is called a derived word or a derivative.

Examples and Observations

"Derivational morphemes are used to change the grammatical categories of words. For example, the derivational morpheme -er is used to transform the verb bake into the noun baker. The morpheme -ly changes the adjective quick into the adverb quickly. We can change adjectives such as happy into nouns such as happiness by using the derivational morpheme -ness. Other common suffixes include -ism, -tion, -able, -ment and -al. Derivational morphemes can also be prefixes, such as un-, in-, pre- and a-.

"Derivational morphemes can be added to free morphemes or to other derivational morphemes. For example, the verb transform consists of the root word form and the prefix trans-, a derivational morpheme. It can become the noun transformation by adding the derivational morpheme -ation. By adding -al to -ation, the adjective transformational is created."
(Lynne Hebert Remson, "Oral Language." Literacy for the New Millennium, ed. by Barbara J. Guzzetti. Praeger, 2007

Derivational Morphemes and Meanings

"Derivational morphemes have clear semantic content. In this sense they are like content words, except that they are not words. . . . [W]hen a derivational morpheme is added to a base, it adds meaning. The derived word may also be of a different grammatical class than the original word, as shown by suffixes such as -able and -ly. When a verb is suffixed with -able, the result is an adjective, as in desire + able. When the suffix -en is added to an adjective, a verb is derived, as in dark + en. One may form a noun from an adjective, as in sweet + ie."
(Victoria Fromkin, Robert Rodman, and Nina Hyams, An Introduction to Language, 10th ed. Cengage, 2013

Derivational Affixes

"Unlike the inflectional affixes, which number only eight in English, the set of derivational affixes is open-ended; that is, there are a potentially infinite number of them (although the number is finite at any one time for a particular speaker). Since it would be impossible to enumerate them exhaustively, let us look at a few representative examples. [In American English the] suffix -ize attaches to a noun and turns it into the corresponding verb, as in criticize, rubberize, vulcanize, pasteurize, mesmerize, and so on. (This suffix can also be added to adjectives, as in normalize, realize, finalize, vitalize, equalize, and so on.) The suffix -ful attaches to a noun and turns it into the corresponding adjective, as in helpful, playful, thoughtful, careful, and so on."
(Frank Parker and Kathryn Riley, Linguistics for Non-Linguists, 2nd ed. Allyn and Bacon, 1994

Inflectional Morphemes and Derivational Morphemes

"Some inflectional endings . . . acquire characteristics of derivational morphemes. These include -ed, -en, -er, -ing and -ly. To make this clear, let us take an example. The morpheme -er can function both as an inflectional morpheme and as a derivational morpheme. As an inflectional morpheme, -er is attached to adjectives to show the comparative as in hotter, describing something as having a higher temperature. As a derivational morpheme, -er is highly productive in forming new nouns. In this use, the morpheme expresses mainly agenthood. It is attached to verbal roots to form nouns as in camper, describing someone who performs the action indicated by the verb. It is attached to adjectival roots to form nouns as in teenager, describing someone as having the quality denoted by the adjective. It is attached to nominal roots to form nouns as in freighter, describing a large ship or aircraft designed for carrying goods."
(Zeki Hamawand, Morphology in English: Word Formation in Cognitive Grammar.

Continuum, 2011)