Original: "Amen" and "alleluia" come from Hebrew, and the threefold "sanctus" derives from the threefold "kadosh" of the Kedusha.
Simplified: The words "amen" and "alleluia" come from the Hebrew language of the Jews. The prayer "santus, sanctus, sanctus," which means "holy, holy, holy," comes from the Jewish prayer "kadosh, kadosh, kadosh."