In ASL, what function do non-manual markers serve?

In American Sign Language (ASL), non-manual markers serve an important role in conveying both emphasis and grammatical structure. These markers include facial expressions, head movements, and body posture, which are essential for communicating meanings that are not directly expressed through hand signs alone. For example, raising your eyebrows can indicate a yes/no question, while shaking your head can signify negation.

Using non-manual markers effectively can enhance the clarity of the message, indicating tone or intensity, much like intonation does in spoken languages. They also help structure sentences, signaling aspects such as questions, conditional phrases, and emotions. This integration of non-manual markers with signed language allows for nuanced communication, ensuring that the intended meaning is conveyed accurately.