An enraged Ukrainian man stabbed a compatriot for speaking Russian at a Brooklyn bar in a booze-fueled spat that’s now being investigated as a hate crime, The Post has learned. Andrii Meleshkov, who was born and raised in Eastern Ukraine and has a Russian mother, said he was at Signature karaoke bar in Sheepshead Bay celebrating a friend’s birthday last Monday when Oleg Sulyma, 31, sat down at his table and started hurling “profanities” at him and his buddies. “You look Russian,” Sulyma, who is Ukrainian, sneered, according to prosecutors.