Two Uses of Going To
Going to is used for future plans you’ve already decided on, and for predictions based on something you can see right now. It’s more certain than “will” because there’s already evidence or a decision made.
Already decided before speaking.
You can see it’s about to happen.
Formula
Examples
The phrase literally describes someone going to a destination. Mentally picture yourself already walking toward the future event — the decision is made, you’re in motion. Will = you’re still standing still deciding. Going to = you’re already moving.