Aktionsart: States vs. Events
Mithun (1991:512–4) uses lexical aspect or Aktionsart to account for the two intransitive verb classes of Colloquial Guaraní: SA verbs denote events (“the activities, accomplishments, and achievements of Vendler 1967, adopted in Van Valin 1990” [1991:513]), whereas SO verbs describe states, characterized by time stability. In Guaraní, SA verbs include go, walk, run, come, swim, dance, play, work, fall, sleep, while typical SO verbs are be sick, be hungry, be wet, be weak, beshort, be round, be wise, be strong/powerful, be lazy. There are very few exceptions, and Mithun provides convincing explanations for them.
In Cariban languages, most time-stable states are not verbs but adverbs/ adjectives or nouns (e.g. Tiriyó kure ‘good, well, pretty’, kaw6 ‘high, tall’, piya ‘small’ [adverbs], mono ‘big (one)’, kainan ‘new (one)’ [nouns]). Nouns and adverbs/adjectives can occur as predicates simply by taking a subject NP (20a)–(20b), or as adverbial complements in a copular construction (1c)–(1d).
(1)

Some state-describing verbs do exist, as seen in Table 1. By itself, the copula does not describe a state, but rather serves as a connector between the state indicating adverbial complement and the subject. The other verbs may conceivably have inceptive/inchoative rather than (or perhaps together with) stative meanings; since the glosses are either taken from secondary sources or are the result of fieldwork on a previously unstudied language, they must be considered approximative.
Table 1. State-describing verbs in Cariban languages.

With this in view, the stative/eventive opposition seems to correlate (though perhaps with exceptions) with a lexical distinction between verbs (denoting events) and adverbs/adjectives and nouns (denoting states) rather than with the distinction between SA and SO intransitive verbs.