What Is Inflectional Morphology (words)

Glossary of Grammatical and Rhetorical Terms

Inflectional morphology is the study of the processes (such as affixation and vowel change) that distinguish the forms of words in certain grammatical categories.

In comparison to many other languages, the inflectional system of Modern English is fairly limited. 

Inflectional morphology is customarily distinguished from derivational morphology (or word formation). As A.Y. Aikhenvald points out, "Derivational morphology results in the creation of a new word with a new meaning. In contrast, inflectional morphology involves an obligatory grammatical specification characteristic of a word class" ("Typological Distinctions in Word-Formation" in Language Typology and Syntactic Description, 2007). This distinction, however, is not always clear-cut.

Examples and Observations

  • Inflectional Categories and Derivational Catgeories
    "The prototypical inflectional categories include number, tense, person, case, gender, and others, all of which usually produce different forms of the same word rather than different words. Thus leaf and leaves, or write and writes, or run and ran are not given separate headwords in dictionaries. Derivational categories, in contrast, do form separate words, so that leaflet, writer, and rerun will figure as separate words in dictionaries. In addition, inflectional categories do not, in general, alter the basic meaning expressed by a word; they merely add specifications to a word or emphasize certain aspects of its meaning. Leaves, for instance, has the same basic meaning as leaf, but adds to this the specification of multiple exemplars of leaves. Derived words, by contrast, generally denote different concepts from their base: leaflet refers to different things from leaf, and the noun writer calls up a somewhat different concept from the verb to write.
    "That said, finding a watertight cross-linguistic definition of 'inflectional' which will let us classify every morphological category as either inflectional or derivational is not easy. . . . [W]e define inflection as those categories of morphology that are regularly responsive to the grammatical environment in which they are expressed. Inflection differs from derivation in that derivation is a lexical matter in which choices are independent of the grammatical environment."​
    (Balthasar Bickel and Johanna Nichols, "Inflectional Morphology." Language Typology and Syntactic Description: Grammatical Categories and the Lexicon, 2nd ed., edited by Timothy Shopen. Cambridge University Press, 2007)
  • Dictionaries and Inflectional Morphology
    "[I]t is not correct to say that dictionaries never have anything to say about inflectional morphology. This is because there are two reasons why a word form such as pianists does not have to be listed, and these reasons are interdependent. The first is that, once we know that an English word is a noun denoting a kind of thing that can be counted (if the noun is pianist or cat, perhaps, but not astonishment or rice), then we can be confident that it will mean simply 'more than one X,' whatever X may be. The second reason is that, unless otherwise specified, we can be confident that the plural form of any countable noun will be formed by adding to the singular form the suffix -s (or rather, the appropriate allomorph of this suffix); in other words, suffixing -s is the regular method of forming plurals.
    "That qualification 'unless otherwise specified' is crucial, however. Any native speaker of English, after a moment's thought, should be able to think of at least two or three nouns that form their plural in some other way than by adding -s: for example, child has the plural form children, tooth has the plural teeth, and man has the plural men. The complete list of such nouns in English is not long, but it includes some that are extremely common. What this means for the dictionary entries for child, tooth, man and the others is that, although nothing has to be said about either the fact that these nouns possess a plural form or about what it means, something does have to be said about how the plural is formed."
    (Andrew Carstairs-McCarthy, An Introduction to English Morphology: Words and Their Structure. Edinburgh University Press, 2002)
  • Eight Regular Morphological Inflections
    "There are eight regular morphological inflections, or grammatically marked forms, that English words can take: plural, possessive, third-person singular present tense, past tense, present participle, past participle, comparative degree, and superlative degree. Most have phonologically sensitive realizations. . . .
    "Modern English has relatively few morphological inflections in comparison with Old English or with other European languages. The inflections and word-class clues that do remain help the listener process incoming language."
    (Marianne Celce-Murcia, Donna M. Brinton, and Janet M. Goodwin, Teaching Pronunciation: A Reference for Teachers of English to Speakers of Other Languages. Cambridge University Press, 1996)
  • Irregular Inflectional Morphology
    "The so-called irregular inflectional morphology or morphological processes (such as internal vowel change or ablaut (sing, sang, sung)) today represent limited historical remnants of former grammatical inflectional systems which were probably semantically based and are now acquired lexically for frequently used lexical items rather than as grammatical systems (Tobin 1993:Ch. 12)."​
    (Yishai Tobin, "Phonology as Human Behavior: Inflectional Systems in English." Advances in Functional Linguistics: Columbia School Beyond Its Origins, ed. by Joseph Davis, Radmila J. Gorup, and Nancy Stern. John Benjamins, 2006)