2NI Future forms

We have different ways of talking about the future. We often use going to (+ infinitive), the present continuous (to be + -ing) or will (+ infinitive). The structure we use depends on the function of what we want to say, whether we are talking about arrangements, plans, predictions, etc.

http://learnenglishteens.britishcouncil.org/grammar-vocabulary/grammar-videos/future-forms

http://www.english-4u.de/future_ex3.htm