Good grammar doesn't reveal your IQ, but it does reveal the quality of your reading and your education - or your absorption therof. So, to refresh my grammar, I shall review "will" and "shall", and you shall listen to me.
The important verb "will" has two conjugations: for plain future, it's "(I or we) shall..." and (You or they) will...". For commands, promises, and assertions, it's the reverse. Simple.