The Prehistory of the Proto-Slavic Abstract Suffix *-ostь and its Baltic Congeners

ABSTRACT The study deals with the origin of the Proto-Slavic adjective abstract suffix *-ostь. Firstly, the existing proposals are systematized and evaluated. It is concluded that the most promising explanation is the one according to which the suffix *-ostь was metanalyzed from regular abstract nouns in *-ь (*zelenь -i ‘the color green’ ← *zelenъ ‘green’) built to an old class of adjectives in *-ostъ < *-osto-, not directly preserved but paralleled in other Indo-European languages (Latin angustus ‘narrow’). The article proceeds to provide a number of observations corroborating and extending this theory. Evidence for the ‘missing link’, i.e. the class of adjectives in *-ostъ, is sought in Old Polish personal names of the type Miłost and in the inferred basis of derivatives parallel to *-ostь, such as the noun *starosta. Furthermore, the Baltic evidence is engaged seriously: in line with recent research, Lithuanian -astis must be treated as cognate – and not borrowing – of Slavic *-ostь, which impacts the diachronic explanation. It is argued that formations such as Lithuanian abstracts in -asta(s) may reflect traces of a class of adjectives in *-asta- < *-osto- as well. The abstract in *-asti- can be considered as yet another meaningful innovation of Proto-Balto-Slavic.