Complex sentence: HMS "Hermes" was an aircraft carrier built for the Royal Navy and was the world's first ship to be designed as an aircraft carrier, although the Imperial Japanese Navy's was the first to be commissioned and launched.
Split into simpler sentences: HMS "Hermes" was an aircraft carrier built for the Royal Navy. She was the world's first ship to be designed as an aircraft carrier, although the Imperial Japanese Navy's was the first to be commissioned and launched.