Suppletion refers to irregularity in the coding of semantic relations. Suppletive forms can be found among both verb stems (go – went) and affixes (boy-s – ox-en). This parameter focuses on suppletion within verb stems, which can be described as the phenomenon in which different stems coexist within a single verbal paradigm. Suppletion may occur across tenses, aspects, other categories, or may be absent in a language.
NoVSuppl: Verb stem suppletion does not exist.
VSupplT: Verb stem suppletion only occurs across tenses.
VSupplA: Verb stem suppletion only occurs across aspects.
VSupplElse: Verb stem suppletion occurs across other lines than tenses and aspects.
 Verb stem suppletion in English is restricted to a particular tense; in other languages, however, it may occur within numerous tenses. Aspect-specific suppletion primarily affects the perfect–imperfect distinction, although it can also apply to other aspectual distinctions (see the Russian id’ot ‘goes’– šol ‘went’; govorit’ ‘to say (impf.)’ – skazat’ ‘to say (pf)’). Whichever parameter value (except NoVSuppl) applies, a detailed description should be provided in the commentary.