There are four different ways in English to talk about the future. You can use the simple future, the going to - future, the present progressive and the present pimple to write or talk about future actions. There is often only a little difference between the future tenses, especially between the going to - future and the present progressive. It also depends on the country and region and on the communication what future tense is used. In written English the simple future is usually used while in spoken English we use the going to - future more often.
Use of the Simple Future Tense
1. to talk about future actions we can't influence or control.
2. to foretell future actions or to express hopes, expectations, fears, offers, promises and refusals.
Key words: I'm sure, I believe, I expect, I hope, I suppose, I think, I'm afraid, I wonder, I fear, I worry, I promise, I guess or perhaps, possibly, surely, probably, maybe
3. with I / we for spontaneous reactions or making promises.
I shall is sometimes used instead of I will.
Use of the going to - Future
1. to talk about future things you intend to do, plan or decided to do.
Did you know that Sarah is in hospital? No, I didn't. I'll visit her this afternoon.
(spontaneous reaction »»» will - future)
Yes, I'm going to visit her next month.
(planned action »»» going to - future)
2. to foretell future actions for which we have proofs that they are going to happen.
Use of the Present Progressive in the future
To talk about future things that are fixed, planned or definitely decided.
The speaker must refer to the future and not to the present.
I am visiting my grandparents tomorrow.
What are you doing next Friday?
Use of the Present Simple in the future
To talk about times of arrivals and departures of traffic and times of events.
The train leaves at 10.20.
The bus goes at 8.30.
When does the concert begin?