USE 2 (future arrangements) might seem a little confusing to an ESL learner because it's completely different from USE 1. Therefore, from my experience, ESL learners tend to make a lot of mistakes as they begin to use it. One mistake is to use the Future Simple to express future arrangements, while the correct tense would be the Present Continuous or the going to form.


I'm going to go to my grandma.
I'm going abroad this summer (in both sentences the speaker is speaking about plans)

I will go to my grandma (the speaker decided to go there in the moment of speaking)

Examples		Use
	He is getting married this month	(Use 2)
	They are swimming in the sea	(Use 1)
	I'm having my first driving lesson this week	(Use 2)
	I'm drinking hot coffee now	(Use 1)

Examples		Use
	Is she eating my cake now?	(Use 1)
	Are they having the party on Friday or Saturday?	(Use 2)
	Are you meeting David today?	(Use 2)
	Is Mary having breakfast now?	(Use 1)

Examples		Use
	He is not joking	(Use 1)
	We aren't waiting for my uncle	(Use 1)
	He is not going to school tomorrow	(Use 2)