Complex sentence: Between 1932 and 1935, Líster received training in the Frunze Military Academy, one of the most respected in the former Soviet Union, and when the Spanish Civil War started, he joined the Republican Army.
Split into simpler sentences: Between 1932 and 1935, Líster received training in the Frunze Military Academy, one of the most respected in the former Soviet Union. When the Spanish Civil War started, he joined the Republican Army.