will-future oder going-to-future
- going to – Plan oder Absicht: I'm going to visit my grandma next weekend.
- going to – sichtbare Anzeichen: Look at the clouds! It's going to rain.
- will – spontane Entscheidung: The phone is ringing. – I'll get it!
- will – Vermutung, Vorhersage, Versprechen: I think it will be sunny tomorrow. I will help you.
Für feste Termine (Fahrplan, Stundenplan) nimmt man das simple present: The train leaves at 8.