This printable handout includes the formation of the future simple (will+infinitive) and the its different uses: promises, offers, predictions and immediate decisions. There are some exercises to practise this.
We use will+infinitive in the following cases:
1) Immediate decisions
E.G.: 'll have pizza and a Coke.
A) John is sick. B) Really? I'll visit him today.
2) Offers (when you help somebody) and requests (when you want something from somebody)
E.G.: I'll help you with those bags, they look very heavy.
You're very good at maths. Will you help me with this exercise?
E.G.: I promise I'll study for the exam.
4) Predictions with no evidence
E.G.: In the future, people will be taller and fatter.