Future: going to & will

The difference between going to and will is dependent on when the decision was made.

If it is made during the time of talking it is considered to be spontaneous or unplanned. For this we use the will future,
e.g. It’s cold in the office so I will (I’ll) put the heating on.

Decisions made prior to the time of talking are considered planned. For these events we use the going to future,
e.g. I am going to attend a trade fair tomorrow.

The ‘will’ future:

(the ‘unplanned’ future) The will future is formed by adding an infinitive verb to will:

 – will + infinitive

The ‘going to’ future

(the ‘planned’ future) The going to future is formed with the correct form of the verb to be with going to then adding the infinitive

 – to be + going to + infinitive

(unplanned) – Someone phones …… “ I will answer the phone”.
(planned) – We are going to go to the trade fair next week.

(unplanned) We add not after will to form a negative
e.g. Oh no, my car will not start
(planned) We add not after the correct form of to be to form a negative
e.g. I am not going to attend the meeting tomorrow
Note: “
will not” is often shortened to “won’t”
“ going to” sounds like “gonna” in spoken English

(spontaneous) With the will future we simply invert the subject and will
e.g. Will you open the door?
(planned) With the going to future we simple invert the subject and the correct form of the verb to be.
e.g. John, are you going to go to Bremen next week?

(unplanned) – will future – I’ll, you’ll, he’ll, she’ll, it’ll, we’ll, they’ll
(planned) – going to future (to be) – I’m, he’s, she’s, it’s, we’re, they’re …. going