Grammar 1.5

Grammar 1.5
     Will

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 thgis 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)