What is American Sign Language?

American Sign Language (ASL) is a complete, natural 

language that has the same linguistic properties as 

spoken languages, with grammar that differs from 

English. ASL is expressed by movements of the hands and 

face. It is the primary language of many North Americans 

who are deaf and hard of hearing and is used by some 

hearing people as well.

Is sign language the same in other 

countries?

There is no universal sign language. Different sign 

languages are used in different countries or regions. 

For example, British Sign Language (BSL) is a different 

language from ASL, and Americans who know ASL may 

not understand BSL. Some countries adopt features of 

ASL in their sign languages. 

Where did ASL originate?

No person or committee invented ASL. The exact 

beginnings of ASL are not clear, but some suggest that it 

arose more than 200 years ago from the intermixing of 

local sign languages and French Sign Language (LSF, or 

Langue des Signes Française). Today’s ASL includes some 

elements of LSF plus the original local sign languages; 

over time, these have melded and changed into a rich, 

complex, and mature language. Modern ASL and modern 

LSF are distinct languages. While they still contain some 

similar signs, they can no longer be understood by each 

other’s users.

How does ASL compare with spoken 

language?

ASL is a language completely separate and distinct 

from English. It contains all the fundamental features 

of language, with its own rules for pronunciation, word 

formation, and word order. While every language has 

NIDCD Fact Sheet | Hearing and Balance

American Sign Language

A young boy signs “I love you.”

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES ∙ National Institutes of Health

NIDCD...Improving the lives of people with communication disorders
2

ways of signaling different functions, such as asking a 

question rather than making a statement, languages 

differ in how this is done. For example, English speakers 

may ask a question by raising the pitch of their voices 

and by adjusting word order; ASL users ask a question 

by raising their eyebrows, widening their eyes, and tilting 

their bodies forward.

Just as with other languages, specific ways of expressing 

ideas in ASL vary as much as ASL users themselves. In 

addition to individual differences in expression, ASL has 

regional accents and dialects; just as certain English 

words are spoken differently in different parts of the 

country, ASL has regional variations in the rhythm of 

signing, pronunciation, slang, and signs used. Other 

sociological factors, including age and gender, can affect 

ASL usage and contribute to its variety, just as with 

spoken languages.

Fingerspelling is part of ASL and is used to spell out 

English words. In the fingerspelled alphabet, each letter 

corresponds to a distinct handshape. Fingerspelling is 

often used for proper names or to indicate the English 

word for something.

How do most children learn ASL?

Parents are often the source of a child’s early acquisition 

of language, but for children who are deaf, additional 

people may be models for language acquisition. A deaf 

child born to parents who are deaf and who already use 

ASL will begin to acquire ASL as naturally as a hearing 

child picks up spoken language from hearing parents. 

However, for a deaf child with hearing parents who have 

no prior experience with ASL, language may be acquired 

differently. In fact, 9 out of 10 children who are born 

deaf are born to parents who hear. Some hearing parents 

choose to introduce sign language to their deaf children. 

Hearing parents who choose to have their child learn sign 

language often learn it along with their child. Children 

who are deaf and have hearing parents often learn sign 

language through deaf peers and become fluent.

Why emphasize early language 

learning?

Parents should expose a deaf or hard-of-hearing child 

to language (spoken or signed) as soon as possible. 

The earlier a child is exposed to and begins to acquire 

language, the better that child’s language, cognitive, 

and social development will become. Research suggests 

that the first few years of life are the most crucial to 

a child’s development of language skills, and even the 

early months of life can be important for establishing 

successful communication with caregivers. Thanks to 

screening programs in place at almost all hospitals in 

the United States and its territories, newborn babies 

are tested for hearing before they leave the hospital. If 

a baby has hearing loss, this screening gives parents an 

opportunity to learn about communication options. Learn 

more about baby’s hearing screening at https://www.

nidcd.nih.gov/health/your-babys-hearing-screening#8.

Parents can then start their child’s language learning 

process during this important early stage of development. 

What research does the NIDCD support 

on ASL and other sign languages? 

The NIDCD supports research on ASL, including its 

acquisition and characterization. Funded research 

includes studies to understand sign language’s grammar, 

acquisition, and development, and use of sign language 

when spoken language access is compromised by trauma 

or degenerative disease, or when speech is difficult to 

acquire due to early hearing loss or injury to the nervous 

system. 

ASL is a language 

completely separate and 

distinct from English. 

It contains all the 

fundamental features of 

language, with its own 

rules for pronunciation, 

word formation, and 

word order.
3

Teenage boy having a conversation using sign language. 

Study of sign language can also help scientists 

understand the neurobiology of language development. 

In one study, researchers reported that the building of 

complex phrases, whether signed or spoken, engaged 

the same brain areas. Better understanding of the 

neurobiology of language could provide a translational 

foundation for treating injury to the language system, 

for employing signs or gestures in therapy for children 

or adults, and for diagnosing language impairment in 

individuals who are deaf.

The NIDCD is also funding research on sign languages 

created among small communities of people with 

little to no outside influence. Emerging sign languages 

can be used to model the essential elements and 

organization of natural language and to learn about the 

complex interplay between natural human language 

abilities, language environment, and language learning 

outcomes. Visit the NIH Clinical Research Trials and 

You website (https://www.nih.gov/health-information/ 

nih-clinical-research-trials-you) to read about these and 

other clinical trials that are recruiting volunteers.
Where can I find additional information 

about American Sign Language?

The NIDCD maintains a directory of organizations that 

provide information on the normal and disordered 

processes of hearing, balance, taste, smell, voice, 

speech, and language. Visit the NIDCD website at 

https://www.nidcd.nih.gov/directory to search 

the directory.

More NIDCD fact sheets on Hearing and Balance:

} Assistive Devices for People with Hearing, Voice, 

Speech, or Language Disorders

} Cochlear Implants

} Hearing Aids

} Your Baby’s Hearing Screening

Visit the NIDCD website at https://www.nidcd.nih.gov to 

read, print, or download fact sheets.

American Sign Language

NIH Publication No. 11-4756

March 2019

Reprinted March 2020

For more information, contact us at:

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1 Communication Avenue

Bethesda, MD 20892-3456

Toll-free voice: (800) 241-1044

Toll-free TTY: (800) 241-1055

Email: nidcdinfo@nidcd.nih.gov

https://www.nidcd.nih.gov

 Follow the NIDCD on Twitter at @NIDCD

The NIDCD supports and conducts research and 

research training on the normal and disordered 

processes of hearing, balance, taste, smell, voice, 

speech, and language and provides health information, 

based upon scientific discovery, to the public.

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