Confidence
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Recognition Mode
Sign Language
Translation Log
Start signing — translations appear here.
Linguistic Architecture
Sign languages are complete natural languages — not gesture systems, not codes for spoken language. They have rich, independent grammars. This is what Semaphore currently tracks and what remains on the roadmap.
Grammar · Facial
Non-Manual Markers
Facial expressions in sign languages are full grammatical morphemes — not emotional decoration. Raised eyebrows mark yes/no questions; furrowed brows with a forward head tilt mark wh-questions (who, what, where, why). Head movements encode negation, affirmation, and topic boundaries. Mouth morphemes — mm (normal/calmly), th (carelessly), oo (small/thin), pah (suddenly/finally) — are independent grammatical morphemes with no English equivalent. Eye gaze signals role shift, verb agreement, and discourse structure. None of this is optional or stylistic.
Baker & Padden (1978) · Liddell (1980) · Sandler & Lillo-Martin (2006) · Wilbur (2000)
Morphology · Syntax
Spatial Grammar
Signers establish referents at locations in the signing space (loci) and encode pronouns, verb agreement, and spatial relationships by pointing to or moving between those loci. Agreement verbs arc through space to index subject and object simultaneously — expressing in a single movement what English needs a full clause for. Role shift (body lean + gaze realignment) marks perspective-taking and reported speech. This simultaneous, spatial morphology is typologically unlike any spoken language syntax.
Padden (1988) · Klima & Bellugi (1979) · Emmorey (2002)
Phonology · Structure
Sign Components
Stokoe (1960) established that each sign decomposes into discrete sub-lexical primes analogous to phonemes: (1) handshape, (2) location relative to the body, (3) movement, (4) palm orientation, and (5) non-manual features. Minimal pairs exist across all five dimensions — ASL MOTHER and FATHER differ only in location (chin vs. forehead). This discovery demonstrated that sign languages are not holistic gestures but structured phonological systems, overturning a century of assumptions about language modality.
Stokoe (1960) · Battison (1978) · Brentari (1998)
Current Scope
What Semaphore Reads Now
The current model reads 21 hand landmarks per hand (42 normalized floats: x, y coordinates translated to wrist origin, scaled by max absolute value) and classifies static ASL fingerspelling A–Z. This captures handshape and orientation only. Movement trajectories, body-relative location, non-manual features, and temporal sequences are not yet modeled. Full sentence-level ASL interpretation requires multi-frame temporal architectures incorporating face mesh, body pose, and bilateral hand landmarks simultaneously — an active area of research (Li et al., 2020; Desai et al., 2024).
Architecture: MediaPipe Tasks Vision · ONNX Runtime Web · Roadmap in progress
References
- Stokoe, W. C. (1960). Sign language structure: An outline of the visual communication system of the American deaf. Studies in Linguistics, Occasional Papers No. 8. University of Buffalo.
- Battison, R. (1978). Lexical Borrowing in American Sign Language. Linstok Press.
- Baker, C., & Padden, C. (1978). Focusing on the nonmanual components of ASL. In P. Siple (Ed.), Understanding Language Through Sign Language Research (pp. 27–57). Academic Press.
- Klima, E. S., & Bellugi, U. (1979). The Signs of Language. Harvard University Press.
- Liddell, S. K. (1980). American Sign Language Syntax. Mouton.
- Padden, C. A. (1988). Interaction of Morphology and Syntax in American Sign Language. Garland.
- Brentari, D. (1998). A Prosodic Model of Sign Language Phonology. MIT Press.
- Emmorey, K. (2002). Language, Cognition, and the Brain: Insights from Sign Language Research. Lawrence Erlbaum Associates.
- Sandler, W., & Lillo-Martin, D. (2006). Sign Language and Linguistic Universals. Cambridge University Press.
- Wilbur, R. B. (2000). Phonological and prosodic layering of nonmanuals in American Sign Language. In K. Emmorey & H. Lane (Eds.), The Signs of Language Revisited (pp. 61–96). Lawrence Erlbaum Associates.
- Li, D., Rodriguez, C., Yu, X., & Li, H. (2020). Word-level deep sign language recognition from video: A new large-scale dataset and methods comparison. Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision (WACV) (pp. 1459–1469).
- Desai, S., Berger, A., Minakov, D., Santa Cruz, M., Singh, A., Sepahi, K., … Bhatt, S. (2024). ASL Citizen: A community-sourced dataset for advancing isolated sign language recognition. Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).
Learn ASL
Free, high-quality resources for learning American Sign Language — from fingerspelling to fluency.
Dictionary · Video
Handspeak
Large video dictionary of ASL signs with clear demonstrations of handshape, location, movement, and palm orientation. Good for looking up individual signs and studying regional variation.
Curriculum · Free
Lifeprint / ASL University
Dr. Bill Vicars' free online ASL curriculum — structured lessons from beginner to advanced, covering vocabulary, grammar, fingerspelling, and Deaf culture. The most complete free course available.
Dictionary · Academic
Gallaudet Dictionary
Gallaudet University's online ASL dictionary, produced by the world's only university designed for Deaf and hard-of-hearing students. Authoritative source for ASL lexicon.
Video · Community
ASL That
Community-driven video dictionary with thousands of entries, including slang, cultural signs, and less-common vocabulary. User submissions reviewed by Deaf community members.
Practice · Interactive
SignSchool
Structured ASL courses with video lessons, quizzes, and spaced repetition. Good for systematic vocabulary building. Free tier available with premium courses for deeper study.
Fingerspelling · Drill
Fingerspelling.xyz
Dedicated fingerspelling trainer with receptive and expressive practice modes. Adjustable speed, word lists, and letter-specific drills. Essential for building the muscle memory Semaphore is designed to recognize.
Common Signs
60 essential ASL signs — greetings, pronouns, emotions, numbers, and animals. Each entry shows the handshape, location, and movement in plain language.
Greeting
Hello / Hi
HELLO Live
Open B-hand, fingers together, palm out. Touch fingertips to forehead then sweep hand outward — like a casual salute.
Greeting
Goodbye
GOODBYE
Open hand, palm facing the person. Fold fingers down then open them back up — a natural wave condensed into one motion.
Greeting
How Are You?
HOW YOU?
Both bent hands, knuckles together, palms in. Rotate wrists outward to flat hands, then point at the person. Eyebrows raised for yes/no question.
Greeting
Nice to Meet You
NICE MEET YOU
NICE: flat hand wipes forward across palm. MEET: both 1-hands (index fingers up) move toward each other until they meet. YOU: point at person.
Greeting
My Name Is…
MY NAME ___
MY: flat hand on chest. NAME: both H-hands (index + middle extended), dominant hand taps twice across non-dominant. Then fingerspell your name.
Greeting
Please
PLEASE Live
Flat open hand on chest. Rub in a circular motion — like rubbing your heart with gratitude.
Greeting
Thank You
THANK-YOU Live
Flat hand starts at chin, palm toward face. Move hand forward and slightly down toward the person — like blowing appreciation outward.
Greeting
Sorry / Excuse Me
SORRY Live
A-hand (fist with thumb at side). Place on chest and rub in a circular motion. Sincere expression reinforces meaning.
Pronoun
I / Me
ME
Index finger points to your own chest. Simple, natural, universal.
Pronoun
You
YOU
Index finger points directly at the person you're addressing. For plural "you all," sweep the index finger across the group.
Pronoun
He / She / They
HE / SHE / THEY
ASL has no gender in pronouns. Point index finger toward the referent's established locus in signing space — or at the person directly.
Pronoun
We / Us
WE
Index finger touches one shoulder, then arcs across the body to touch the other shoulder — sweeping to include yourself and others.
Pronoun
My / Mine
MY
Flat open hand (B-hand), palm facing in. Press firmly on your own chest.
Phrase
I Love You
ILY Live
Extend thumb, index finger, and pinky — ring and middle fingers folded down. This single handshape combines I (index), L (thumb+index), and Y (thumb+pinky).
Phrase
Yes
YES Live
S-hand (fist). Nod the fist up and down at wrist — mimicking a head nod with your hand.
Phrase
No
NO Live
Index and middle finger snap closed against the thumb twice — like the mouth of a hand saying "no, no."
Phrase
Help
HELP
Flat A-hand (like a thumbs-up) rests on the palm of the other flat hand. Lift both hands upward together — one supporting the other.
Phrase
Good
GOOD Live
Flat hand starts at chin, palm facing in. Move forward and down into the palm of the non-dominant hand — like presenting something excellent.
Phrase
Bad
BAD
Flat hand at chin, palm in. Flip outward and downward — the reverse of GOOD, literally throwing it away.
Phrase
More
MORE Live
Both O-hands (fingers pinched to thumb). Tap fingertips together twice in front of the chest.
Phrase
Stop
STOP Live
Non-dominant flat hand, palm up. Dominant flat hand comes down sharply onto the edge of the non-dominant palm — like a karate chop to halt.
Phrase
Eat / Food
EAT Live
Dominant hand in O-shape (fingertips pinched). Bring to mouth and tap lips once or twice — mimicking putting food in the mouth.
Phrase
Drink / Water
DRINK
C-hand (curved, as if holding a cup). Tilt toward mouth — mimicking drinking from a cup.
Phrase
Sleep
SLEEP
Open hand in front of face, fingers spread. Draw hand downward while closing fingers to O-hand — eyes closing, face relaxing.
Phrase
Home / House
HOME
Flat O-hand (fingers pinched) touches corner of mouth, then moves up and touches the cheek near the ear — combining EAT and SLEEP at home.
Phrase
Friend
FRIEND
Both index fingers hook together — one on top, then flip so the other is on top. Interlocking: a mutual bond.
Phrase
Family
FAMILY
Both F-hands (thumb+index touching), fingertips touching in front. Open and arc outward and around until pinky sides touch — encircling the group.
Phrase
Mother
MOTHER
Open 5-hand, palm toward face. Tap thumb on chin twice. The chin area is the feminine zone in ASL.
Phrase
Father
FATHER
Open 5-hand, palm toward face. Tap thumb on forehead twice. The forehead area is the masculine zone in ASL.
Phrase
Beautiful
BEAUTIFUL
Open hand in front of face, fingers spread. Move in a circular arc around the face while closing to a flat O — like framing a beautiful thing.
Phrase
Understand
UNDERSTAND
S-hand (fist) at temple. Flick index finger upward and open — like a lightbulb switching on inside your head.
Phrase
Don't Know
DON'T-KNOW
Flat hand at forehead, palm in. Flip outward and away, twisting wrist — like wiping away a blank mind.
Emotion
Happy
HAPPY
Flat hand on chest. Brush upward twice with a light, quick motion — like joy rising up from your heart.
Emotion
Sad
SAD
Both open hands in front of face, palms toward you. Draw both hands slowly downward — like a face falling with sorrow.
Emotion
Angry
ANGRY
Curved 5-hand on chest, fingers pointing in. Thrust hand forward and outward while tensing — projecting the feeling outward forcefully.
Emotion
Tired
TIRED
Both bent hands on chest, fingertips touching. Rotate downward and inward so the wrists drop — like the body slumping with fatigue.
Emotion
Sick
SICK
Both bent 5-hands. Middle finger of dominant hand touches forehead; middle finger of non-dominant touches stomach. Bent posture and pained expression reinforce it.
Emotion
Excited
EXCITED
Both open 5-hands on chest, alternating middle fingers brushing upward in outward circles — like excitement bubbling up and spiraling out.
Emotion
Scared / Afraid
SCARED
Both S-hands (fists) in front of chest. Open them suddenly and move toward center — like bracing for impact.
Emotion
Bored
BORED
Index finger tip touches the side of the nose. Twist slightly — a subtle, dismissive gesture of tedium.
Number
1
ONE Live
Index finger extended upward, all other fingers and thumb closed. Palm faces outward.
Number
2
TWO Live
Index and middle fingers extended and spread in a V-shape. Palm faces out.
Number
3
THREE Live
Thumb, index, and middle fingers extended. Ring and pinky closed. Palm out.
Number
4
FOUR Live
All four fingers extended and spread, thumb tucked across palm. Palm faces out.
Number
5
FIVE Live
All five fingers extended and spread wide. Palm faces out — open hand.
Number
6
SIX Live
Pinky and thumb touch at their tips; index, middle, and ring fingers extended upward. Palm faces out.
Number
7
SEVEN Live
Ring finger and thumb touch at their tips; index, middle, and pinky extended. Palm faces out.
Number
8
EIGHT Live
Middle finger and thumb touch; index, ring, and pinky extended. Palm faces out.
Number
9
NINE Live
Index finger and thumb form a circle (like OK); middle, ring, and pinky extended upward. Palm faces out.
Number
10
TEN Live
Thumb extended upward (A-hand). Shake or wiggle the hand — the thumb represents 10 in ASL's base-10 counting system.
Time
Today
TODAY
Both Y-hands (thumb and pinky out), palms up. Drop them downward in front of the body — NOW + DAY combined into one sign.
Time
Tomorrow
TOMORROW
A-hand (fist with thumb up). Place thumb on cheek and arc forward — projecting into the future ahead of you.
Time
Yesterday
YESTERDAY
A-hand, thumb at cheek. Arc backward over the shoulder — moving into the past behind you.
Time
Now
NOW
Both Y-hands (or bent hands), palms up. Drop them downward sharply — landing in the present moment.
Time
Later / After
LATER
L-hand (thumb and index finger forming an L). Thumb on palm of non-dominant hand, rotate dominant hand forward — time moving ahead.
Question
What?
WHAT
Both open hands, palms up. Shake them slightly from side to side — like shrugging "what is it?" Furrowed brows mark it as a wh-question.
Question
Where?
WHERE
Index finger extended, shake it back and forth rapidly from the wrist — scanning for a location. Furrowed brows.
Question
When?
WHEN
Both index fingers extended and pointing. Circle dominant around non-dominant, then tap the tip. Furrowed brows for wh-question.
Question
Who?
WHO
L-hand near chin — thumb up, index pointing forward. Wiggle the index finger from the wrist. Furrowed brows.
Question
Why?
WHY
Fingers touch the forehead, then bring hand down and change to a Y-hand. Furrowed brows — "what's the reason?"
Question
How?
HOW
Both bent hands, knuckles touching. Rotate wrists outward to flat B-hands — unfolding, opening up to show the method.
Animal
Dog
DOG
Pat the thigh with a flat hand, then snap fingers — the universal signal for calling a dog. Done in sequence with a slight head tilt.
Animal
Cat
CAT
F-hand (index+thumb pinched) near the upper lip. Draw outward twice — tracing the whiskers of a cat.
Animal
Bird
BIRD
G-hand (index and thumb extended) at the mouth. Open and close index and thumb together twice — mimicking a beak.
Animal
Fish
FISH
Flat hand, wrist bent, fingers pointing forward. Wiggle the fingertips while moving the hand forward — a fish swimming through water.
Animal
Horse
HORSE
U-hand (index and middle extended) at the side of the head. Bend and unbend the two fingers twice — the large flapping ears of a horse.
Animal
Elephant
ELEPHANT
Bent B-hand at the nose. Sweep hand downward and outward in a long arc — tracing the shape of an elephant's trunk.
Animal
Bear
BEAR
Cross arms over chest, fingertips near shoulders. Scratch both shoulders simultaneously with curled fingers — a bear hugging and clawing.
Animal
Rabbit
RABBIT
Both U-hands (index and middle) crossed at the wrists above the head. Bend and unbend the extended fingers twice — long rabbit ears twitching.
Animal
Snake
SNAKE
Bent V-hand (index and middle curved like fangs) at the mouth. Thrust hand forward in a quick, spiraling motion — a snake striking.
Animal
Lion
LION
Curved 5-hand above the head. Move it backward over the hair in a sweeping arc — tracing the lion's magnificent mane.
Suggestions & Feedback
Working on adding word-level ASL, facial grammar, and more. Have a recommendation, dataset tip, or found a bug? Let us know.