EXPLANATION OF FUTURE FORMS: BE GOING TO, WILL, PRESENT CONTINUOUS

There is no one 'future tense' in English. There are 4 future forms. 

BE GOING TO: PLAN

We use 'going to' when we want to talk about a plan for the future.

• I'm going to see him later today.
• They're going to launch it next month.
• We're going to have lunch first.
• She's going to see what she can do.
• I'm not going to talk for very long.

Notice that this plan does not have to be for the near future.

• When I retire I'm going to go back to Barbados to live.
• In ten years time, I'm going to be boss of my own successful company.

We use 'going to' when we want to make a prediction based on evidence we can see now.

• Look out! That cup is going to fall off.
• Look at those black clouds. It's going to rain soon.
• These figures are really bad. We're going to make a loss.
• You look very tired. You're going to need to stop soon.

We can replace 'going to go' by 'going'.

• I'm going out later.
• She's going to the exhibition tomorrow.

 WILL: PREDICTIONS / SPONTANEOUS DECISION

We can use 'will' to talk about future events we believe to be certain.

• The sun will rise over there tomorrow morning.
• Next year, I'll be 50.
• That plane will be late. It always is.
• There won't be any snow. I'm certain. It's too warm.

Often we add 'perhaps', 'maybe', 'probably', 'possibly' to make the belief less certain.

• I'll probably come back later.
• He'll possibly find out when he sees Jenny.
• Maybe it will be OK.
• Perhaps we'll meet again some day.

We often use 'will' with 'I think' or 'I hope'.

• I think I'll go to bed now.
• I think she'll do well in the job.
• I hope you'll enjoy your stay.
• I hope you won't make too much noise.

We use 'will' at the moment we make a new decision or plan. The thought has just come into our head.

• Bye. I'll phone you when I get there.
• I'll answer that.
• I'll go.
• I won't tell him. I promise.

 PRESENT CONTINUOUS: ARRANGEMENTS

We use the present continuous to talk about things that we have already arranged to do in the future.

• I've got my ticket. I'm leaving on Thursday.
• I'm seeing Julie at 5 and then I'm having dinner with Simon.
• He's picking me up at the airport.
• The company is giving everyone a bonus for Christmas.