Use of the will-future
When do we use the will-future?
The will-future is one future tense. There are other future tenses, e.g. going to-future, Present Progressive, Future Progressive/Continuous and Simple Present.
We use the will-future:
1. future actions happen without the speaker's intention (birthday, weather, etc.)
The sun will shine tomorrow.
Peter will be 15 next Tuesday.
2. predictions, assumptions (I think, I hope, I'm sure, I'm afraid)
I think Sue will arrive in Paris at 6 pm.
3. promises, threats
I promise I will learn the poem by heart.
4. spontaneous actions (not planned)
Hang on! I'll have a word with you.