alternáciu

Alternation, in linguistics, refers to the systematic variation of a word’s form depending on phonological, morphological, or syntactic context. It describes how a morpheme can surface with different shapes while maintaining a stable meaning or grammatical function. Alternation patterns are regular and learnable, forming part of a language’s morphophonology.

There are several types of alternation. Phonological or morphophonemic alternation involves changes in sound within a word or its stem that accompany related forms, such as vowel changes or consonant mutation. Allomorphy is a closely related concept in which a single morpheme has multiple realizations (for example, the English plural endings -s, -es, or zero plural). Stem alternations occur when the root itself changes across inflected forms, as in man/men or foot/feet.

Common sources of alternation include historical sound changes that become synchronized with morphology (historical ablaut or umlaut), productive affixation that induces predictable vowel or consonant changes, and phonological harmony processes that affect affixes depending on the root’s vowels or consonants.

Alternation plays a crucial role in grammar and word formation. It can underlie irregular verb conjugations, noun plurals, comparative forms, and case endings, while also providing evidence for historical developments and language change. Analysts describe these patterns using concepts such as morphophonology and allomorphy to account for how surface forms relate to underlying representations.

See also: allomorphy, morphophonology, ablaut, umlaut, vowel harmony.