The Buryat forms -gšA (“present / semelfactive” participle / nomen actoris) and -АAšA (“constant participle”) are characterized in fairly contradictory ways in grammars: researchers have ascribed quite diff erent temporal and aspectual meanings to them. Further, these two forms can encode not only the event, but also its participants (hence nomen actoris). Their functional range is much narrower than that of other participles. The paper shows that these forms indicate not the TAM-characteristics of the event marked by the participle, but the discourse status of its relativized participant, the referent of the head noun: they mark it as bearing the focus of attention based on either the speaker’s knowledge (-gšA), or the common knowledge of the speaker and the addressee (-AAšA). Thus we propose a new distinctive parameter for Buryat participles, which is pertinent also through the lens of Mongolic studies and general typology.