system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Russian last names: Uncle Ruslan's last name is Tsarni, but bomber's last name is Tsarnaev?

Do Russian surnames change? Upon marriage or region or...?
gpt
It's not a Russian name.  It's a Chechen one with a Russian suffix appended to the end.  This was commonly done for all sorts of non-Russian nationalities in the Russian Imperial days, and they've persisted.  Some people prefer to use the non Russified version.