Simple Future

Simple Future has two different forms in English: "will" and "be going to."

FORM Will

[will + verb]

Examples:
You will help him later.
Will you help him later?
You will not help him later.

USE 1 "Will" to Express a Voluntary Action

 A voluntary action is one the speaker offers to do for someone else.

We also use "will" when we request that someone help us or volunteer to do something for us.

USE 2 "Will" to Express a Promise

I will call you when I arrive.

Don't worry, I'll be careful.

I won't tell anyone your secret.

FORM Be Going To

[am/is/are + going to + verb]

Examples:
You are going to meet Jane tonight.
Are you going to meet Jane tonight?
You are not going to meet Jane tonight.

USE 3 "Be going to" to Express a Plan

"Be going to" expresses that something is a plan.

Examples:

He is going to spend his vacation in Hawaii.

She is not going to spend her vacation in Hawaii.

USE 4 "Will" or "Be Going to" to Express a Prediction

Both "will" and "be going to" can express the idea of a general prediction about the future.

Examples:

The year 2222 will be a very interesting year.

The year 2222 is going to be a very interesting year.