If you throw me out the window, I'll leave a grieving wife. Bring me back, but through the door, You'll see someone giving life. What am I?

Why this works

This riddle plays with the transformation of words by adding or removing the letter 'n'. When you take 'n' out of "window," you are left with "widow," which refers to a grieving wife. Conversely, when you add 'n' to "door," it becomes "donor," someone who gives life, often in the context of organ donation. This clever use of wordplay highlights how a single letter can dramatically change meanings and create a playful connection between the concepts of loss and giving.