- We use "be about to" to say that something will happen almost immediately.
(Example)
(1) Take your seats, please. The show is about to begin.
(2) I was about to go out when the phone rang.
- We use the present progressive with a word or phrase expressing future time to talk about something that will happen because we have planned or arranged.
(Example)
(1) We're leaving on Saturday morning.
(2) I'm having a party next week - do you want to come?
