verbs had almost gone entirely extinct by the time of written records, while Sanskrit and Ancient Greek preserve them more clearly. Proposed endings At least the following sets of endings existed: Primary ("present") endings used for: Present tense of the indicative mood of imperfective verbs. Subjunctive mood Secondary ("past" or "tenseless") endings used for: Past tense of the indicative mood of imperfective verbs. Indicative mood of perfective verbs. Optative mood Stative endings used for Indicative mood of stative verbs. Imperative endings used for Imperative mood of all verbs. Note that, from a diachronic perspective, the secondary endings were actually the more basic ones, while the primary endings were formed from them by adding a suffix, originally -i in the active voice and -r in the middle voice. The more central subfamilies of Indo-European have innovated by replacing the middle-voice -r with the -i of the active voice. Traditional accounts say that the first-person singular primary ending is the only form where athematic verbs used a different ending from thematic verbs. Newer accounts by , and are similar, with the proto-forms modernized using laryngeal notation. Sihler, however, notes that many of the most archaic languages have third-person singular forms missing a t and proposes an alternative t-less thematic ending along with the standard ending. Greek and Balto-Slavic have t-less forms in thematic actives, whereas Vedic and Hittite have t-less athematic middle forms. uses the t-less forms as the starting point for a radical rethinking of the thematic endings, based primarily on Greek and Lithuanian. These proposals are still controversial, however. Active eventive endings Middle eventive endings Stative endings A second conjugation has been proposed in Jay Jasanoff's h₂e-conjugation theory. Svensson (2001) suggests *-h₂éy for the second and third dual stative endings, on the basis of evidence from Indo-Iranian, Tocharian, and Gaulish. Verb aspects Proto-Indo-European verbs belonged to one of three aspect classes: Stative verbs depicted a state of being. Eventive verbs expressed events. These could be further divided between: Perfective verbs depicting actions viewed as punctual, an entire process without attention to internal details, completed as a whole or not completed at all. No distinction in tense was made. Imperfective verbs depicting durative, ongoing or repeated action, with attention to internal details. This included the time of speaking; separate endings were used for present or future events in contrast to past events. The terminology around the stative, perfective and imperfective aspects