The Lexikon der indogermanischen Verben (LIV, Lexicon of Indo-European Verbs) is an etymological dictionary of the Proto-Indo-European (PIE) verb. The first edition appeared in 1998, edited by Helmut Rix. A second edition followed in 2001. The book may be seen as an update to the verb entries of the Indogermanisches etymologisches Wörterbuch (IEW) by Julius Pokorny. It was the first dictionary fully utilizing the modern three-laryngeal theory with reconstructions of Indo-European verbal roots.

The LIV's hypothesis about aspect

The authors of the LIV assume a dichotomy between telic verbs (terminated: for example, 'to light up') and atelic verbs (ongoing: for example, 'to shine') in early stages of Proto-Indo-European. Before the daughter languages split off, aspect emerged as a new grammatical category. Telic verbs were interpreted as aorist forms, and the missing present was formed with various suffixes (for example, ) and the nasal infix, all of which are supposed to come from old grammatical forms of uncertain meaning. Atelic verbs were interpreted as present forms, and the missing aorist was formed with the suffix -s-, yielding the sigmatic aorist. This hypothesis is used to explain various phenomena: In addition to the present and the aorist, the following aspects are assumed:

Entries

The lexical part contains for each verbal root

Indices

The book includes

Reception and criticism

Other PIE dictionaries and grammars