1. She is on the phone, so call back later.

2. She is on the line, so call back later.
3. She is on another phone, so call back later.
4. She is on another line, so call back later.
-----------------------
Are they all grammatical?

1 answer

All are grammatically correct, but I'd use only #4. Even better is to ask for the caller's number and say, "I'll ask her to call you back."
Similar Questions
  1. 1. He called me later.2. He rang me back. 3. He gave me a ring back. 4. He telephoned me back. 5. He made a phone call to me
    1. answers icon 1 answer
    1. answers icon 1 answer
    1. answers icon 1 answer
  2. Thank you very much, Writeacher.Here are some more phrasal verbs related to phone calls I'd like you to check. Thank you again!
    1. answers icon 1 answer
more similar questions