The autor deals with the underdescribed problem of choosing the formant of the indefinite pronoun -kolwiek or -ś in the contemporary Northern Borderland Polish, namely the overuse of the affix -kolwiek at the expense of -ś (for instance: W kącie ogródka rozrosły się boże drzewko, lilie i jakiekolwiek piękne drzewko). The heretofore explanation of this pecularity, i.e. functional asymmetry of the Polish affix -kolwiek and its Russian dictionary equivalent –нибудь, was completed by the author who points at Lithuanian as the accomplice (together with Russian) of substituting affix -ś with -kolwiek. Lithuanian indefinite pronouns share functions analogically to Russian pronouns: kažin corresponds to the affix -то, nors to the affix –нибудь. The case of -kolwiek superseding -ś is commonly observed in Northern Borderland references that were influence by Lithuanian.