1.
to be using the telephone :
He's on the telephone at the moment.
You're wanted (= sb wants to speak to you) on the telephone.
2.
( BrE ) to have a telephone in your home or place of work :
We're not on the telephone at the cottage.
1.
to be using the telephone :
He's on the telephone at the moment.
You're wanted (= sb wants to speak to you) on the telephone.
2.
( BrE ) to have a telephone in your home or place of work :
We're not on the telephone at the cottage.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005