In English we can talk about the future using different tenses and auxiliaries. Many students think that we use WILL to form the future tense, but grammarians often say there is no “future tense”, only “ways of expressing future". Most times we talk about the future we do not use WILL, and many of the times we use WILL we are not talking about the future.

PLANS

Plans are the kind of things we write in our agenda, how we are going to organize our future. When talking about plans, we use the Present Continuous. Since this tense is mostly used to talk about things that are happening now, to make clear we are talking about the future and not the present, we must use a future time expression to say when that thing is going to happen (or we already know from the context).

-    I am playing tennis (present: this is what I am doing now) -    I am playing tennis tomorrow morning (future: this is what I am going to do tomorrow morning) More examples: -    I can’t go with you tomorrow, I’m helping dad in the garden -    She’s coming home next week -    I’m starting university next year But we can also use the form Be Going To (there is no difference): -    I’m going to help dad in the garden -    She’s going to have a baby in two months -    Are you going to stay here or are you coming with me? (both forms mixed)

TIMETABLES & PROGRAMMES

When talking about timetables, programmes or similar (for example: public transport, cinema times, classes, etc.) we use the Simple Present tense:

-    My new course starts on Monday -    The train to Paris leaves at 5.30 -    The shops open at 9.00

DECISIONS

We use WILL (negative: WON'T /wəʊnt/) when we decide to do something at the moment of speaking: We make a decision, and at that very moment we say it:

-    Your phone's ringing! - Ok, I'll take it, but where is it? -    Somebody knocked on the door. I’ll see who it is -    Oh, sorry, I dropped all the soup. Don’t worry, I’ll clean it -    It's nine o'clock? Oh damn, I won't go to the cinema then, I would be late But if the decision was made in the past, then we can’t use “will”, we must use “Be Going To”: -    I can’t go with you because I’m going to play tennis with Kevin -    I bought these boots because I’m going to climb the Everest with grandpa -    She's going to plant some trees in her garden, I think you should go and help her Decisions and plans are often the same thing (if you have a plan you probably have made a decision before) so don't worry about the difference, they both are used with Going To, so no problem: -    I'm going to play tennis with John tomorrow  (this is a decision made in the past and also a plan)

PREDICTIONS

We use the form Be Going To when we predict the future based on evidence, objective facts.

In this case there is something in the present telling us what is going to happen in the future, so this kind of prediction is really a deduction (sometimes a very clever deduction, sometimes just common sense) -    Those clouds are so dark, I think it’s going to rain soon -    I’m worried about this crack on the wall, this is going to be a problem

But other times, when we talk about the future, we are not making a deduction, we are really making a subjective prediction based on our intuition or in what we know, believe or imagine.

-    If you go to England take an umbrella, it will probably rain every day
-    Don’t worry about the wedding, it will be fine, you’ll look great
-    This kid will be someone important when he grows up

In practice, predictions with GOING TO are more solid (because they are based on facts) and more probable than predictions made with WILL. For this reason, we often break the rule and use GOING TO for subjective predictions when we want to express the idea that our prediction is very solid and we are very sure about it:

-    Don’t worry about the wedding, everything’s going to be ok, you’re going to look great
-    I know I’m going to be happy there, I can feel it in my bones. 

When talking, it is very common tu use GONNA instead of “Going To” (with or without the verb To be):

-    Oh wow, you gonna be the prettiest girl in the party! -    Wait for me, I’m gonna finish this first and then we can go -    You gonna wait here all day?

If you want to know more about the future you can continue reading here.