be/get/keep, etc. in touch
B1
to communicate or continue to communicate with someone by telephoning, or writing to them
Dictionary examples:
My grandma finally got in touch by sending a pigeon with a letter! (0.0)
My dog and I are always in touch. He barks, I give treats. (0.0)
He tried to get in touch with aliens using a tin can phone. (0.0)
Jane and I never kept in touch after college. (23.3)
Are you still in touch with any of your old school friends? (26.5)