Simple Future Tense

It is used to express an action which has not occurred yet and will occur after saying or in future.

Pattern 1
   (+) Subject + shall/will + verb 1 + object 
   (-)  Subject + shall/will + not + verb 1 + object 
   (?) Will/shall + subject + verb 1 + object 

Examples: 
  1. (+) We shall bake a cake tonight
      (-)  We shall not bake a cake tonight
      (?)  Shall we bake a cake tonight?

  2. (+) You will take part in the meeting next week
      (-)  You will not take part in the meeting next week
      (?)  Will you take part in the meeting next week? 

Pattern 2
   (+) Subject + to be + going to + object
   (-)  Subject + to be+ not + going to + object 
   (?) To be + subject + going to + object

Examples:
     (+) You are going to be a doctor
     (-) You are not going to be a doctor
     (?) Are you going to be a doctor?

     (+) She is going to buy a cell phone next month
     (-) She is not going to buy a cell phone next month
     (?) Is she going to buy cell phone next month?

Note:

1). Shall is used with the first person subject (I, we), while will can be used with all kinds of subjects.

2). Shall/will is used to express the future when we have no plan before. It means that we decide to do something at the time of speaking and it is not arranged before.
  
    Examples:
      • It’s so hot in this room. I will turn the air con on.
      • We have run out of papers, haven’t we? I’ll go and buy some.

3). Will can also be used to predict about something.
       
    Examples:
      • It will rain tonight.
      • People won't go to Jupiter before the 22nd century.

4). To be going to is used to express something that has been arranged before.
       
     Examples:
      • I am going to visit Bali next year.
      • He is going to see his doctor this evening.