Complex sentence: Northwest Airlines Corp. (often abbreviated NWA) was a major United States airline founded in 1926 and absorbed into Delta Air Lines Inc. by a merger approved on October 29,2008, making Delta the largest airline in the world.
Split into simpler sentences: Northwest Airlines Corp. (often abbreviated NWA) was a major United States airline founded in 1926 and absorbed into Delta Air Lines Inc. by a merger. Approved on October 29,2008, the merger made Delta the largest airline in the world.