Suppletions

Suppletions, or suppletion, is a linguistic phenomenon in which the forms of a word in different grammatical contexts come from distinct roots rather than a single, regular stem. In a suppletive paradigm, surface forms show little or no phonological or etymological relation to one another, so inflected forms cannot be predicted by applying regular sound changes to a single base.

The phenomenon is most visible in verb inflection. Classic English examples include be, with am, is, are, was, and were; and go, with went. These forms cannot be derived from a single stem through ordinary morphophonology. Suppletion also appears in nouns and adjectives in some languages, such as man/men and child/children, where singular and plural or comparative forms do not share a common overt root. While less frequent, some languages exhibit suppletive patterns across other parts of speech or across multiple grammatical categories.

Types of suppletion can be full or partial. Full suppletion replaces the stem for certain forms, while partial or discontinuous suppletion involves only some forms or a mixture of related and unrelated roots within a paradigm. Historical processes such as phonological changes, analogy, or borrowing from other languages can unlink forms and give rise to suppletion.

In linguistic analysis, suppletion is treated as irregular lexical data: sentences and inflection tables may record multiple stems under a single lexical entry, or treat each form as its own lexeme within a unified paradigm. It is distinct from regular allomorphy, where variation follows predictable phonological rules from a shared stem. Suppletion is attested across language families, especially in irregular verb systems and in certain noun and adjective forms.