Complex sentence: Walter "Gulle" Oesau (28 June 1913--11 May 1944) was a German World War II fighter ace who served in the "Luftwaffe" from 1934 until his death in 1944.
Split into simpler sentences: Walter "Gulle" Oesau (28 June 1913--11 May 1944) was a German fighter pilot during World War II. A fighter ace, he served in the Luftwaffe from 1934 until his death in 1944.