Hi,
I'd like you to clarify something for me. It's about use of present continous and going to when we are talking about future.
To begin with I'd like to say that [color=blue]we can use them interchangeably when we talk about future actions that have been planned before the moment of speaking[/color] ( I am not sure about it though.)
Exemples :
I am redecorating/ going to redecorate my room on Sunday.
Im meeting Mr. Johnson on Friday , but I am not sure whether the sentence : Im going to meet Mr. Johnson on Friday has the same meaning. Does it?
Prediction - when we are talking about an event in the future basing on evidence visible with the naked eye we use going to AND NOT present continuous.
Exemple :
We see clouds gathering in the sky so we can say " Damn , it's going to rain ! We'd better go home"
Tell me if my reasoning is good

Best wishes
