Complex sentence: Helmut Oberlander, born 1924, is a Canadian resident whose citizenship has been revoked twice since 1995 because of his work as a translator for a Nazi-era death squad.
Split into simpler sentences: Helmut Oberlander, born 1924, is a Canadian resident whose citizenship has been revoked twice since 1995. The reason given is his work as a translator for a Nazi-era death squad.