Present Simple, Present Continuous, Future Simple és a be going to hogyan utal a jövőre?

PS: schedule, timetable (tehát menetrend szerint végzett dolgoknál)

example: The train leaves at 10 p.m.

PC: talking about plans for the future (+ adverb of time)

tehát ha konkrét időben már előre megtervezett tevékenységet fogsz végezni.

example: I'm visiting my grandmother tonight.

"Going to" future:

to talk/ask about plans, actions that depend on the speaker

example: I'm going to visit my grandmother.

Are you going to buy vegetables?

to talk about predictions that have signs in the past.

example: It's cloudy, it's going to rain.