Basic contrast: will, going to, present continuous

•  Will:
  •  is normally known as the predictive future, and describes known facts,  what we suppose is true, or something we think, guess or calculate about the future
    • I’ll be late this evening
    • The company will make a profit next year
    • Most of the family will be probably there
      
  • can also take the form of an assumption
    • That’ll be Jim at the door 
  • to express an immediate decision, made at the same time you speak or write
    • I’ll take this one
    • I’ll call you later
      
• Be going to
  • describes intentions or plans. At the moment of speaking, plans have already been made
    • I’m going to wait here until Carol gets back
  • to describe or predict an event whose cause is present or evident
    • Look at that tree! It’s going to fall
    • Judging from the grey sky, it’s going to rain anyway
      
  • 
    
• Present continuous
  • describes fixed arrangements, especially social and travel arrangements. A time reference is usually included. It’s very similar to the going to future
    • I’m having a party next week end  (I am going to have a party next week)

• Present simple
  • for fixed timetables, schedules, and arrangements
    • Don’t forget it closes at 10.30 on Sundays
  • is used to refer to future time in future time clauses
    • When we get there, we’ll have dinner
    • Present perfect: can be used instead of present simple when the completion of the action is emphasised
      • When we’ve had a rest, we’ll go out
  • and is also used to describe fixed events which are not simply the wishes of the speaker, or calendar references
    • Tom retires in three years
    • Christmas is on a Tuesday next year
• Future continuous
  • Describes an event which will be in progress during a period of time at a future point
    • Come round in the morning. I’ll be painting in the kitchen
    • I’ll be working all the weekend
      
  • Can describe events which are going to happen anyway, rather than events which we choose to make happen
    • I won’t bother to fix a time to see you, because i’ll be calling into the office anyway several times next week.
  • In some contexts future continuous also sounds more polite than will
    • Will you be going to the shops later? If you go, could you get me some milk?
  • It can also be used to refer to fixed arrangements and plans
    • The band will be performing live in Paris this summer
• Future perfect (simple and continuous forms)
  • for something that will be finished before a time in the future
    • Maybe you’ll have done your various duties by the end of the evening
  • refers to time which we look back at from a future point
    • In two years I’ll’have finished the book
    • By the end of the month, I’ll have been working for this firm for a year
  • Can also be used to express an assumption on the part of the speaker
    • You won’t have heard the news, of course.

Other ways of referring to the future

• Is / are to be: used to describe formal arrrangements
  • All students are to assemble in the hall at 9.00
• Be about to, be on the point of: refer to the next moment
  • I think the play is about to start now
    
• Be due to: refers to scheduled times
  • The play is due to start in five minutes
  • Ann’s flight is due a 6.20
    
• Just / just about to: can be used to describe something on the point of happening
  • Hurry up! The train is just leaving / just about to leave

Other future references

• Hope: can be followed by either present or future forms
  • I hope it doesn’t rain  /  I hope it won’t rain
• Other verbs followed by will (most verbs of thinking)
  
  • I expect the train will be late
  • I doubt whether United will win
• Shall: (first person) British Englisn and declining in use. For some users shall is used in foemal speech and written language