suppletie

Suppletie, or suppletion, is a linguistic phenomenon in which the inflected forms of a word are derived from different etymological roots rather than from a single stem through productive affixation. The term is widely used in the study of morphology to describe irregular inflection patterns that cannot be predicted by standard rules applying to a word’s base form.

In practice, a suppletive paradigm uses two or more distinct stems to express different grammatical categories, such as tense, person, or degree. The choice of stem is determined by grammatical context rather than by uniform affixation. Suppletion often appears most clearly in verb systems but can also involve adjectives, pronouns, or other parts of speech in some languages.

English provides well-known examples. The verb to be has present forms am, are, is and past forms was, were, forms that originate from different historical roots. The past tense of go is went, a form derived from a different verb root than the present tense go. Such pairs illustrate how modern inflection can rely on separate origins rather than a single, regularly formed stem. Some discussions extend the idea to comparative adjectives like good/better or bad/worse, though the etymology of these pairs is debated and varies by language.

Across languages, suppletion is a recognized mechanism for expressing morphology when historical change leaves irregular, non-derivable forms in a paradigm. It highlights the complexity of language history and the limits of productive, rule-governed inflection.