There is no one future tense in English. Instead, several verb forms and auxiliaries might be used to express the future.
1 will + infinitve:(shall after I and we in formal English)
1.) a prediction without proof and which is based upon your own opinion
I think Labour will win the elections. (That is my opinion.)
2.)in the First Conditional but never after if
If you aren’t careful, you’ll break that glass.
3.) a decision or an intention made at the moment of speaking
Someone is knockingat the door. I’ll open it.
2 - to be going to + infinitive:
1.) a prediction based on a present fact or some evidence
Look at the sky. It ‘s going to be a lovelyday. (The sky proves this.)
2.) a decision or an intention made before the moment of speaking
When she grows up, she is going to be a ballet dancer.
3 the PresentProgressive or Continuous
1.) a future arrangement (made an appointment)
I’m seeing Aïda next month. (You have bought the tickets already.)
4 the Present Simple1.) the certain future of a timetable or calendar
My flight leaves at 10.00.
It is my birthday tomorrow.
2.) after if, when, before and so on in the First Conditional
If theweather turns bad, the picnic will be cancelled.
5 the Future Continuous: will + be + -ing form
1.) an activity that will be in progress before and after a time inthe future
Don’t phone at 8.00, because we will be having dinner.
2.) a future event that will happen in he natural course of events
Don’t worry about our guests. They’ll bearriving any minute now.
6 the Future Perfect
1.) an action that will be completed before a definite time in the future.
I’ll have done all my work by this evening.