Here's why:
* Sign language is visual: Meaning is conveyed through handshapes, facial expressions, and body movements. Patting your head could be a part of a larger sign, but it wouldn't stand alone.
* Context is crucial: The meaning of a sign depends heavily on its context. For example, a pat on the head could be a gesture of comfort or encouragement, but it could also be a sign of affection, depending on the situation and the relationship between the people involved.
To understand the meaning of a sign, it's important to consider the entire context, including:
* The handshape: What is the hand doing?
* The facial expression: What is the signer's face conveying?
* The body movement: How is the signer's body moving?
* The surrounding context: What is happening around the signer?
If you're interested in learning sign language, it's best to study from a qualified instructor or use reliable resources.