New learners of American Sign Language often spend their first months focused entirely on the hands: handshape, movement, location, palm orientation. Then a Deaf signer watches them and says something that changes everything — the signs were correct, but the sentence made no sense. The reason is almost always the same. In ASL, a large part of the grammar does not happen on the hands at all. It happens on the face.
Non-manual markers: grammar without hands
Linguists call these facial and body behaviours non-manual markers or non-manual signals. They include eyebrow position, eye gaze, head movement, shoulder position, cheek tension and specific mouth shapes. Crucially, they are not decoration and not simply emotion: they function grammatically, the way intonation and word order function in spoken English.
The comparison with intonation is a useful one. In English, “You’re coming” and “You’re coming?” contain identical words; only the pitch tells you it is a question. In ASL, the same set of signs can be a statement, a question or a condition depending on what the eyebrows and head are doing while the hands move.
Eyebrows do the heavy lifting
| Structure | Eyebrows | Other cues |
|---|---|---|
| Yes/no question | Raised | Head and body lean slightly forward, eyes widen, hold at the end |
| Wh-question (who, what, where, why, how) | Furrowed / lowered | Head tilt forward, slight squint, question sign often held |
| Topicalisation | Raised | Brief pause after the topic, then the comment |
| Conditional (“if…”) | Raised during the condition | Neutral or new marker on the result clause |
| Rhetorical question | Raised | Signer answers their own question immediately |
Notice the pattern that surprises most beginners: yes/no questions raise the brows, while wh-questions lower them. Hearing learners often do the opposite, because in English a question feels like something that should go “up”. Getting this backwards is one of the most common sources of confusion in early conversations.
The mouth is not silent
ASL uses specific mouth configurations, often called mouth morphemes, that add meaning much like adverbs do in English. They are made with the mouth and cheeks, not by mouthing English words.
- A tight, drawn mouth shape can indicate that something was done close, thin, or with precision.
- A relaxed, slightly open mouth with a gentle rhythm can indicate that something is regular, normal or comfortable.
- Puffed cheeks typically convey largeness, fullness or a long duration.
- Pressed or tense lips can indicate effort, difficulty or intensity.
Two sentences with identical handshapes can therefore mean “he drove there normally” or “he drove there for an exhausting long stretch”, depending entirely on what the mouth is doing. Removing the mouth morpheme does not make the sentence neutral; it makes it incomplete.
Head and body carry meaning too
- Headshake for negation. A side-to-side headshake produced while signing negates the sentence, and it can negate a clause even when no explicit negative sign is used.
- Head nod for affirmation. Nodding while signing can confirm or assert, and is often used to close a statement.
- Body shift for role-taking. Turning the shoulders slightly to one side and then the other allows a signer to represent two characters in a conversation without naming them repeatedly.
- Eye gaze for reference. Looking toward a point in the signing space links what is being said to a person or object established earlier there.
This use of space and gaze is one of the features that makes signed languages structurally different from spoken ones, rather than simply a translation of them.
Grammar versus emotion
An important distinction: facial expression in ASL serves two separate jobs at once. Grammatical markers indicate sentence type and structure. Affective expression conveys feeling, exactly as it does for everyone. Fluent signers layer both simultaneously, which is why a signer can ask a wh-question with furrowed brows while clearly looking amused.
For learners this means that “putting on an expressive face” is not the goal. Random exaggerated expressions do not make signing more fluent; they make it noisier. What matters is producing the right marker, at the right moment, for the right duration — typically for exactly as long as the relevant clause lasts.
Common learner mistakes
- The flat face. Signing with a neutral expression throughout removes the grammar entirely and can read as robotic or unclear.
- Mouthing full English words. Silently pronouncing English while signing interferes with ASL mouth morphemes and pulls the sentence toward English structure.
- Dropping the marker too early. Raised brows must be held across the whole question, not flashed at the start.
- Looking at your own hands. Eye contact matters both socially and grammatically; the face of the person signing is where the listener is looking.
- Assuming universality. ASL is one of many sign languages. British Sign Language, Libras and others are distinct languages with their own grammar and their own non-manual systems.
How to practise
Record yourself signing short sentences and watch the video with the sound off, paying attention only to your face. Ask whether someone could tell, without seeing your hands, whether you were asking a yes/no question, a wh-question or making a statement. Practising in front of a mirror helps, but video is more honest.
Above all, watch fluent Deaf signers as much as possible. Non-manual grammar is absorbed far more efficiently through observation than through explanation, and engaging respectfully with the Deaf community is part of learning the language rather than an optional extra.
If you would like a structured starting point, Cursa offers free online sign language courses covering vocabulary, fingerspelling and grammar, including the non-manual features that make signing clear and natural.
