GRAMMAR:

FUTURE TENSES:

There are many ways of expressing the future in English depending on meaning. We can use:

WILL + Infinitive
-To predict what's going to happen based on past experience or opinion.
                You must go to India - You will enjoy it.
-In more formal contexts for arrangements which have been made in some detail.
                The tour will begin at 9.30, you will need good walking shoes.
-For decisions which are made on the spur of the moment.
                I think I will go to Paris

(We use WON'T in negative sentences) 

GOING TO + Infinitive
-To predict something that you hav evidence for.
               Look at those clouds-  I am sure it is going to rain.
-To express intentions or decisions.
              I am going to see The Museum of Modern Art when I get to NY.

SHALL + Infinitive
-To talk about the future instead of will with I and We although it is used less nowadays than previously.
            I shall certain travel first class next time I go abroad.
-For offers.
           Shall I carry your bags?