-Express future actions decided at the moment of speaking.
I think I will buy new clothes.
I will help you.
I will buy a drink.
It will be ok.
I won’t travel by bus.
Used to predict future based on personal opinions or experiences rather than specific evidences. We often use WILL with: I am sure, I am certain, I don’t think, I know etc…
Don’t worry, I am sure you will pass your exam.
I don’t think I will talk to him anymore.
Express future plans decided before the moment of speaking.
-Something that is likely to happen
I am going to be kind.
He is going to start working.
Look at the clouds. It is going to rain.
Download this WILL vs GOING TO PDF that you can read anywhere.