Non-Manual Markers

Grammatical elements in sign languages conveyed through facial expressions, head movements, eye gaze, and body posture rather than hand movements. In American Sign Language, non-manual markers are essential for conveying grammatical information such as questions (raised eyebrows for yes/no questions, furrowed brows for WH-questions), negation (head shake), topicalization (raised eyebrows with head tilt), and conditional statements. ASL learners commonly make errors with non-manual markers, either omitting them or timing them incorrectly. These features can be detected through video analysis for automated feedback in ASL learning systems.