will/going to
When I am older I will/I am going to build a house.

Why is 'will' the correct form and not 'going to'?

'going to do sth' is about intentions and plans, whereas 'will' about immediate decisions and predictions. So I can't really get it. Can anyone help me?

Question

will/going to
When I am older I will/I am going to build a house.

Why is 'will' the correct form and not 'going to'?

'going to do sth' is about intentions and plans, whereas 'will' about immediate decisions and predictions. So I can't really get it. Can anyone help me?

Answer

Without context "am going to" is equally correct there. The only reason why "will" might be preferable is if you're practising 1st conditional.

Answer

Will can also be for not 100% sure plans - you can't be 100% sure you will build a house - it's more like a dream of the future. That's why will is better than going to in this case...If it was - next month I'm going to start building my house that would be fine, but it's not a certainty, hence 'will'...

Hope this helps, Teacher Zowee :)

Answer

Both are fine and used equally to state intentions in the future.