How do I move an event to be a sub-event?

I'm following the platformed tutorial and on page 7 it explains how to move an event and make it a sub-event. No matter what I do I can't seem to make it look like the image example. Either the black line appears above the event I want to drop it into or below. The black line never indents.

Cannot see the image you mentioned but you can press S to create a sub event.

Move the cursor a little to the right to get it to indent.

Ah thanks! Yep pressing S did the trick. I tried dragging that thing all over the place and couldn't find a spot that would cause the indent to happen. But pressing S works for me so thanks!

It won't let me do it period. I copy/pasted an event just with a different level and it refuses to let that event become a sub-event. I NEED THIS TO WORK. (I'm working on Flip the Robot Monkey, and the STEMFuse guide doesn't mention that the "On Collision with Exit/Go to Level 2 event must be copied and replaced with Levels 3+4 so you can go to other levels. It just assumes that you know to copy/paste it) All I get is the cannot move event message. This is SUPER frustrating since I have no idea how to get it to work without changing the order of the events.

Triggered events can be sub-events. However you are not allowed to have two triggers in the same event branch (e.g. a trigger as a sub-event to another trigger), as that doesn't make sense.

As I said in my previous post, you just need to drag an event block and move the mouse to the right a little to get it to show the insert mark as indented, which means it will drop it as a sub-event. If Construct doesn't let you do that, it's probably because it would be an invalid event, for example the restriction with triggers.