การใช้ be to กับ be about to

Be to and be about to

We use be to for a future event that is officially arranged. It is often used in news reports.

The Queen is to visit Portugal in November.
The Student Games are to take place in Melbourne next year.

We could also use the present continuous here.
The Queen is visiting Portugal in November.

We use be about to for the very near future.
The plane is at the end of the runway. It is about to take off.
Do you want to say goodbye to our visitors? They‘re about to leave.