**We use "will" for:
-on the spot decisions:
I'm tired. I'll take a nap.
-Predictions based on what we know:
You'll lose weight with this workout.
-Promises, offers, threats, hopes:
I promise you'll feel better right away.
Note: After time words (while, before, after, until, when, if, etc.) we don't use "will". We use the simple present:
I'll call you when I reach Brazil (NOT: When I will reach) BUT When will he call? (question word)
***EXERCISE.
1.- That's very expensive. I won't buy it
.
2.- I'm sure. I'll buy the disc.
3.- I hope you'll win the competition.
4.-I'll call you before I leave.
5.- When you come?
