Dear native English speakers,
What's the difference between the sentences below?
(a) I'm cooking dinner this evening.
(b) I'll be cooking dinner this evening.
(c) I'm going to cook dinner this evening.
(a) is present continuous. If it is already evening it something you are doing at the moment and it is ongoing i.e. you are currently making dinner. You can use the continuous present for actions you haven't started but have been arranged i.e. you have arranged to make dinner this evening and it is not yet evening.
"Why don't we go on a picnic tomorrow?"
(a)”Sorry, I'm learning English all day tomorrow."
(b)"Sorry, I'll be learning English all day tomorrow."
(c)"Sorry, I'm going to learn English all day tomorrow."