1. a prediction (without proof), a promise/threat, offer
> I
will clean the pan for you.
2. something is planned, prediction (with proof)
> He hasn't studied at all, so he is going to fail the test.
3. Something is planned in the near future
> We are visiting my grandmother this afternoon
4. Something happens according to a schedule
> The train leaves at 8am.
5. Something will happen while something else is taking place
> I will be eating dinner while you are driving home.