Future Simple 
Утвердительные 
S+Will+V1
I will help you with homework 
Отрицательные
S+Won't+V1
She won't pass the exams 
Вопросительное
Will+S+V1?
Will you come to me tomorrow

Случаи употребления:

a)      Предположения, основанные на личном опыте или мнении(predictions based on what we think or imagine)
I think He will be late for the meeting.
b)      Незапланированное решение (on the spot decision)
Is her birthday today? I'll buy her some flowers.

c)      Просьба, предложение, угрозы, обещания (request, offer, threats,promises)
Don't worry. I will help you.

d)      Неотвратимые события в будущем ( inevitable events in the future)
In two weeks there will be my birthday.