Will / Going to

Just a summary contrasting both expressions:

WILL
1. Decision just made 
Oh, there is a fire: I’ll call the police immediately!
2. Predictions about the future (Science, weather forecast, fortune teller…)                  
We’ll have sun and fine weather tomorrow.
3. Opinion (I think…/In my opinion,…/I’m sure…/I’m afraid…)
I’m sure you’ll pass; don’t worry!
4. Offers
I’ll help you with your homework.

BE GOING TO
1. Decision previously made 
A– Why are you calling Ann?
B– I’m going to invite her to dinner.
2. Predictions with evidence
Look, that woman is going to faint.
3. Intentions and plans
I’m going to repair my bicycle

WILL
Negations in the will-future – Exercise
Questions in the will-future – Exercise 1
Questions in the will-future – Exercise 2
Sentences and questions in the will-future - Exercise 1
Sentences and questions in the will-future - Exercise 2
will-future – Statements – Exercise
GOING TO
going to-future – Statements – Exercise
Negations in the going to-future – Exercise
Questions in the going to-future – Exercise 1
Questions in the going to-future – Exercise 2
Sentences and questions in the going to-future – Exercise 1
Sentences and questions in the going to-future – Exercise 2
Sentences and questions in the going to-future – Exercise 3
MIXED
will or going to-future – Exercise 1
will or going to-future – Exercise 2