Complex sentence: John Oliver Johnstone (January 21,1892--February, 1969) was an American track and field athlete who competed in the 1912 Summer Olympics where he finished sixth in the high jump competition.
Split into simpler sentences: John Oliver Johnstone (January 21,1892--February, 1969) was an American track and field athlete who competed in the 1912 Summer Olympics. In 1912 he finished sixth in the high jump competition.