in addition to knowing sign language, it is also helpful to know something about how deaf people communicate. since they rely so much on actions, deaf people are generally not very formal when they talk, and may touch your arm or shoulder a lot to make sure you know what they're saying. it is not seen as rude among deaf people to lightly touch someone you do not know to get their attention. it's also okay to wave your hands or hit the table or floor. also, lots of eye contact is necessary