Complex sentence: Two months later they attempted to support a major offensive by the Imperial Japanese Army to push the United States Marines off Guadalcanal in the Battle of the Santa Cruz Islands where they crippled one US carrier and damaged another in exchange for damage to and a light carrier.
Split into simpler sentences: Two months later, they attempted to support a major offensive by the Imperial Japanese Army to push the United States Marines off Guadalcanal. This resulted in the Battle of the Santa Cruz Islands where they crippled one American carrier and damaged another in exchange for damage to and a light carrier.