"strong verbs" or primary verbs, which had a past tense originating from the statives, and "weak verbs" or secondary verbs, whose past tense used the new dental suffix. The original primary statives (preterite-presents) also used the dental suffix, and a few primary ye-suffix presents also came to use the weak past rather than the strong past, such as *wurkijaną "to work" ~ *wurhtē and *þunkijaną "to think, to consider" ~ *þunhtē. However, these verbs, having no secondary derivational suffix, attached the dental suffix directly to the root with no intervening vowel, causing irregular changes through the Germanic spirant law. Ending-wise, the strong and weak pasts converged on each other; the weak past used descendants of the secondary eventive endings, while the strong past preserved the stative endings only in the singular, and used secondary eventive endings in the dual and plural. Balto-Slavic The stative aspect was reduced to relics already in the Balto-Slavic, with very little of it reconstructable. The aorist and indicative past tense merged, creating the Slavic aorist. Baltic lost the aorist, while it survived in Proto-Slavic. Modern Slavic languages have since mostly lost the aorist, but it survives in Bulgarian, Macedonian, Serbo-Croatian and Sorbian. Slavic innovated a new imperfect tense, which appeared in Old Church Slavonic and still exists in the same languages as the aorist. A new past tense was also created in the modern languages to replace or complement the aorist and imperfect, using a periphrastic combination of the copula and the so-called "l-participle", originally a deverbal adjective. In many languages today, the copula was dropped in this formation, turning the participle itself into the past tense. The Slavic languages innovated an entirely new aspectual distinction between imperfective and perfective verbs, based on derivational formations. See also Sanskrit verbs Ancient Greek verbs Indo-European copula Lexikon der indogermanischen Verben (Lexicon of the Indo-European Verbs) Notes References Bibliography Verb Linguistic morphology Indo-European verbs