|The sign for "why" is
made by touching your forehead with the fingers of your dominant hand. (Or
just putting the hand near your forehead.)
While bringing your hand forward and down a bit, change it to the letter "y," keeping your palm facing you.
Here is another version of the sign, "WHY." Notice the ending handshape? The index finger isn't bent. The middle finger and sometimes both the middle finger and the ring finger "wiggle" a couple times.
All material copyright © 1996 by Dr. William Vicars