Plans and arrangements

To summarise

When we talk about things in the future that we have already planned and arranged to do, we use the present continuous. We often use only small selection of verbs to communicate this. eg go out; see; visit; meet; stay; come; go; have.

-> I’m going out on Friday.

I’m seeing Tiffiny at 2 o’clock.
I’m visiting family at the weekend.
I’m meeting Mr Obama in front of Tesco.
I’m staying with Julie this weekend.

GOING TO + verb

Of course here GOING TO + verb is also fine:

I’m going to meet Mr Obama in front of Tesco.

However it would not be correct to say: *I go to meet Mr Obama” or * “I meet Mr Obama in front of Tesco.”

(the only main note on this is that this is becoming more acceptable in Text English, when you’re using your mobile phone and you want to use fewer characters)