Will/shall + verb
- Predictions without evidence,
- Spontaneous decisions.
- Promises
- Offers
We will give it back tomorrow.
Mum thinks it will rain, I'm not sure though.
I think I will go to the cinema!
To be going to + verb
- Predictions with evidence
- Intentions
- future plans
(but not 100%)
We agreed that we are going to go to the cinema.
Look at those dark clouds! I think it is going to rain.