To sign 'sup' (a casual version of 'what's up'), start by forming an open handshape with your dominant hand and bending your middle finger forward. Place the tip of your middle finger lightly against your chest. Brush your hand upward and slightly outward in a quick, single motion. Pair this with a casual facial expression, often tilting your chin up slightly to match the informal greeting.
Sign 'hey' with a casual wave, then sign 'sup' by brushing your bent middle finger upward on your chest while tilting your chin up to greet your friend.
Point to the person you are talking to, then sign 'sup' while raising your eyebrows slightly to show you are asking them a direct question about how they are doing.
Shake your head and sign 'nothing' with a relaxed expression, then sign 'sup' to effortlessly turn the greeting back to your conversation partner.
Sign 'hey' with a casual wave, then sign 'sup' by brushing your bent middle finger upward on your chest while tilting your chin up to greet your friend.
Point to the person you are talking to, then sign 'sup' while raising your eyebrows slightly to show you are asking them a direct question about how they are doing.
Shake your head and sign 'nothing' with a relaxed expression, then sign 'sup' to effortlessly turn the greeting back to your conversation partner.
No, just like in spoken English, 'sup' is slang and highly informal. You should use the standard signs for 'how are you' when greeting a boss, teacher, or someone you don't know well.
The standard 'what's up' is usually signed with both hands brushing up the chest simultaneously. 'Sup' is the casual, abbreviated version signed with just one hand, matching the shortened slang.
You don't have to, but many signers will casually mouth 'sup' or 'what's up' while doing the sign. The most important non-manual marker is the relaxed facial expression and slight chin tilt.
