Proto-Slavic *pero

→ Belarusian пяро (inherited)

→ Belarusian пярэсты (affix)

→ Czech pero (inherited)

→ Lower Sorbian pjero (inherited)

→ Upper Sorbian pjerjo (inherited)

→ Macedonian перо (inherited)

→ Polish pióro (inherited)

→ Polabian perü (inherited)

→ Serbo-Croatian pero (inherited)

→ Serbo-Croatian перо (inherited)

→ Slovak pero (inherited)

→ Slovene pero (inherited)

→ Albanian fier (cognate)