Student or Learner
call back [INTRANSITIVE/TRANSITIVE]: call someone back to telephone someone again, or to telephone someone who telephoned you earlier.
- I’ll call you back when I’ve heard something.
I can't distinguish the difference betwen 'call again' and 'call back'. Can we use them interchangeably?
- I’ll call you again when I’ve heard something.
You call someone back when they called you first.
You call someone again when you called them first.