How do I detect a collision between two colliders?

My character uses Unity’s Character Controller. The ground uses a Mesh Collider. If I set the ground to be a trigger, the character will fall through the floor. How do I detect when the player hits the ground?

EDIT: I’m currently working around this by raycasting and using a sentinel bool. Seems like such a cludgy fix though :[

Trigger only causes the game objects pass by each other so that they would “Trigger” an effect and not collide. You have to un-check the trigger.

Hope this helps!