will/shall + be + verb + -ing
Future continuous or the future progressive is used to talk about an action that will be in progress at a moment in the future.
I will be lying on the beach by this time tomorrow.
We shall be flying to Russia on Friday.
They will be handling the case themselves.
We use the future perfect continuous to talk about parallel actions in the future that is, two or more actions that happen at the same time.
When he is doing his homework, she will be cleaning the kitchen.
By 21h tomorrow morning I will be doing the garden while they clean the house.
This afternoon they will be cleaning the house, preparing the meal and having a drink together.
We can use the future perfect continuous to predict the present or to say/guess what might be happening in any given situation.
Let them be alone, they will be deciding his future.
If you call him now, He’ll be talking to his mum.
I wouldn’t go in there, They will be discussing important things.
Let’s not arrive before 20h, they will be preparing the dinner.