Derivation can be contrasted with
inflection, in that derivation produces a new word (a distinct
lexeme), whereas inflection produces grammatical variants (or forms) of the same word. Generally speaking, inflection applies in more or less regular patterns to all members of a
part of speech (for example, nearly every
English verb adds
-s for the third person singular present tense), while derivation follows less consistent patterns (for example, the
nominalizing suffix
-ity can be used with the adjectives
modern and
dense, but not with
open or
strong). However, derivations and inflections can share homonyms, that being,
morphemes that have the same sound, but not the same meaning. For example, when the affix
-er is added to an adjective, as in
small-er, it acts as an inflection, but when added to a verb, as in
cook-er, it acts as a derivation. A derivation can produce a
lexeme with a different part of speech but does not necessarily. For example, the derivation of the word
uncommon from
common +
un- (a derivational morpheme) does not change its part of speech (both are adjectives). An important distinction between derivational and inflectional morphology lies in the content/function of a listeme. Derivational morphology changes both the meaning and the content of a listeme, while inflectional morphology doesn't change the meaning, but changes the function. A non-exhaustive list of derivational morphemes in English:
-ful, -able, im-, un-, -ing, -er. A non-exhaustive list of inflectional morphemes in English:
-er, -est, -ing, -en, -ed, -s. ==Derivation and other types of word formation==