How to Sign "Hi" in American Sign Language (ASL)

In ASL, "hi" is signed by extending your hand with palm facing forward at about shoulder height, then waving your fingers back and forth. The casual greeting comes from people's natural way of waving. It's one of the first signs that new learners pick up. You can change how big or small you make the wave depending on whether you're being formal or casual with someone. Since it looks just like regular waving, almost everyone understands this sign, even if they don't know ASL.