To espress actions in progress.
Will + be + -ing.
Example: I will be studing all day.
BE GOING TO
It is used for plans.
I am going to fly to Milan.
To talk about future events in timetables.
My flight leaves on Wednesday morning.
For predictions and spontaneous decisions.
Maybe I will come with you.
PRESENT CONTINOUS ( is an alternative)
To talk about plans in the near future.
I am listening to you.