Proto-Slavic *sъ̀nъ

→ Belarusian сон (inherited)

→ Bulgarian сън (inherited)

→ Old Church Slavonic сънъ (inherited)

→ Upper Sorbian són (inherited)

→ Macedonian сон (inherited)

→ Polish sen (inherited)

→ Russian сон (inherited)

→ Serbo-Croatian san (inherited)

→ Serbo-Croatian сан (inherited)

→ Slovak sen (inherited)

→ Ukrainian сон (inherited)

→ Old Czech sen (inherited)