Proto-Slavic *kъ(n)

→ Czech k (inherited)

→ Czech ku (inherited)

→ Old Church Slavonic къ (inherited)

→ Lower Sorbian k (inherited)

→ Macedonian кон (inherited)

→ Macedonian доцна (inherited)

→ Polish Gdańsk (derived)

→ Polish ku (inherited)

→ Russian к (inherited)

→ Russian ко (inherited)

→ Old Irish co (cognate)

→ Serbo-Croatian k (inherited)

→ Serbo-Croatian к (inherited)

→ Old Novgorodian ко (inherited)