Complex sentence: In 1508, he joined Juan Ponce de Leon to explore Puerto Rico and prospect for gold, and in 1511, he fought under Ponce de Leon to repress the Caribs and the Tainos who had joined forces in Puerto Rico in a great revolt against the Spaniards.
Split into simpler sentences: In 1508, he joined Juan Ponce de Leon to explore Puerto Rico and prospect for gold. He fought under Ponce de Leon in 1511, to repress the Caribs and the Tainos who had joined forces in Puerto Rico in a great revolt against the Spaniards.