Pressing and unpressing a key

How can I make it so that if I press a key, it sets a property to TRUE, and when I let go of the key, it turns back to FALSE?

what i’m trying to do is make someone be able to move a certain way, but only when you hold down the correct button aswell. And when that button is not held down and you try to move, you move differently.

expression controllers or multiple key sensors [one with inverted output]…

Inverting the output might work…could it also have something to do with true and false pulses? If the action reacts to a true pulse and stops on a false pulse? Does that work? Because i’ve been trying that out and it doesn’t seem to have good results…

What would the expression look like? lol sorry if I seem like I know little…it’s probably because it’s true