Complex sentence: The inaugural Liverpool City Region mayoral election will be held on 4 May 2017 to elect the Liverpool City Region Combined Authority, subsequent elections will be held May 2020 and then every four years after that.
Split into simpler sentences: The inaugural Liverpool City Region mayoral election was held on 4 May 2017 to elect the Liverpool City Region Combined Authority. Subsequent elections will be held May 2020 and then every four years after that.