alternate between (people or things)
To switch between two or more different people or things. We are going to alternate between the lead and the understudy at today's rehearsal. The air conditioner alternates between settings depending on the temperature, so I don't think it will get too cold in here. I'm going to alternate between the two microphones, and you tell me which one sounds better on the sound system.
Farlex Dictionary of Idioms. © 2022 Farlex, Inc, all rights reserved.
alternate between (someone and someone else)and alternate between something and something else
to choose or change between two persons or things alternately. The job will alternate between Gil and Ed. The maid will alternate between the first floor and the second floor.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.