The Truth About Mutual Intelligibility: Can ASL Speakers Understand BSL?
No, ASL speakers cannot naturally understand BSL because they are two entirely distinct languages with different historical roots, grammars, and manual alphabets. Despite both being used in English-speaking countries, American Sign Language (ASL) and British Sign Language (BSL) share less than 30% of their vocabulary, making them as different as English is from Russian or Cantonese.
In my years working within international Deaf advocacy circles, I have often seen the confusion on a student’s face when they realize that “Sign Language” is not a universal tongue. If you are an ASL user traveling to London, you will likely find yourself relying on Visual Gestural Communication (VGC) rather than your native signs to get your point across.
Key Takeaways: ASL vs. BSL
- Linguistic Origins: ASL is derived from French Sign Language (LSF), while BSL is part of the BANZSL (British, Australian, and New Zealand Sign Language) family.
- Manual Alphabets: ASL uses a one-handed alphabet, whereas BSL uses a two-handed alphabet.
- Vocabulary Overlap: There is only a 30% lexical similarity between the two languages.
- Grammar: Both languages use unique spatial grammar and facial expressions (Non-Manual Markers) that do not translate directly.
Why Can’t ASL Speakers Understand BSL? The Historical Divide
To understand why can ASL speakers understand BSL is a resounding “no,” we have to look back to the early 19th century. Many hearing people assume that because the United States and the United Kingdom share a spoken language, their signed languages must be related. This is a fundamental misunderstanding of Deaf history.
The Gallaudet and Clerc Connection
In 1815, Thomas Hopkins Gallaudet traveled from America to Europe to learn how to teach Deaf children. He was rejected by the Braidwood Academy in London, which kept its British signing methods a “trade secret.”
Instead, Gallaudet went to Paris and met Laurent Clerc, a teacher of French Sign Language (LSF). They brought LSF back to America, which evolved into modern ASL. Meanwhile, BSL continued its independent development in the UK. This historical snub is the reason an American Deaf person is more likely to understand a French signer than a British one.
The Linguistic “Family Tree”
- ASL Family: French Sign Language (LSF) → American Sign Language (ASL).
- BSL Family: Old British Sign Language → British Sign Language (BSL), Auslan (Australia), and NZSL (New Zealand).
Technical Comparison: ASL vs. BSL
When we analyze the mechanics of the two languages, the barriers to understanding become even clearer. ASL and BSL differ in their phonology (the way signs are formed) and their morphology (how signs are structured).
The Manual Alphabet (Fingerspelling)
This is the most immediate barrier. If an ASL speaker tries to spell their name to a BSL speaker, they will likely be met with total confusion.
| Feature | American Sign Language (ASL) | British Sign Language (BSL) |
|---|---|---|
| Hands Used | One Hand | Two Hands |
| Vowels | Pointing to thumb/fingers is NOT used | Pointing to fingers on the opposite hand |
| Origin | French/European influence | Indigenous British development |
| Speed | Generally faster for single-handed dexterity | Rapid but requires both hands |
Lexical Differences (Vocabulary)
In my experience testing these differences with native signers, we found that even basic nouns like “Mother,” “Father,” or “Water” are completely different. In ASL, the sign for “Mother” involves a thumb to the chin with an open hand. In BSL, the sign typically involves tapping the side of the head with two fingers (the letter ‘M’).
Non-Manual Markers (NMMs)
Both languages rely heavily on Non-Manual Markers—facial expressions, head tilts, and shoulder movements. However, the “accent” or intensity of these markers varies. An ASL user might find the facial grammar of a BSL user to be “dialectically” foreign, much like a thick regional accent in spoken language.
The “False Friends” in Sign Language
Just like “embarazada” in Spanish sounds like “embarrassed” but means “pregnant,” ASL and BSL have “False Friend” signs. These are signs that look identical but have wildly different meanings.
- The “V” Handshape: In ASL, two fingers pointed up can mean the number “two” or “to see.” In BSL, depending on the movement, it could have a very different grammatical function or numerical value.
- The “A” Handshape: A closed fist with the thumb out in ASL is the letter A. In BSL, this handshape is used in several specific verbs that have no phonetic relation to the letter.
Step-by-Step Guide: How to Communicate if You Are an ASL Speaker Meeting a BSL Speaker
If you find yourself in a situation where can ASL speakers understand BSL becomes a practical problem rather than a theoretical one, follow these steps to bridge the gap.
Step 1: Establish a “Baseline”
Don’t jump straight into complex signing. Start with Universal Gestures. Pointing, mimicking the action of eating, or showing a “thumbs up” are generally understood globally.
Step 2: Use International Sign (IS)
International Sign is not a full language but a “pidgin” used at international Deaf events (like the Deaflympics or WFD Congress). It relies more on iconic signs—signs that look like what they represent.
- Practice Iconicity: Instead of using the ASL sign for “Car,” mimic the steering wheel movement.
Step 3: Switch to the Two-Handed Alphabet (for BSL)
If you are an ASL user, learning the BSL manual alphabet is the fastest way to facilitate understanding. It takes about 20 minutes to memorize and allows you to spell out words when signs fail.
Step 4: Rely on Written English
Since most ASL and BSL users are bilingual in written English, a smartphone notepad or a physical piece of paper is the ultimate “universal translator” between these two specific communities.
The Impact of Geography and Culture on Signing
ASL is currently the most dominant sign language globally due to the export of American media and the influence of Gallaudet University—the world’s only liberal arts university for the Deaf.
However, BSL has a fierce and proud cultural heritage in the UK. The British Deaf Association (BDA) has fought for the legal recognition of BSL, which was finally achieved through the BSL Act 2022.
Regional Dialects
It is also worth noting that both languages have internal dialects. An ASL speaker from New York signs differently than one from Texas (Black ASL is a prominent example). Similarly, a BSL speaker from Glasgow has different signs for “colors” and “numbers” than someone from London. This adds a second layer of complexity to the can ASL speakers understand BSL question.
Summary of Major Differences
To help visualize why these two languages are so distinct, I’ve compiled this data based on linguistic research and field observations.
Comparison Table: ASL vs. BSL Mechanics
| Linguistic Element | ASL (American) | BSL (British) |
|---|---|---|
| Language Family | French Sign Language Family | BANZSL Family |
| Alphabet | One-handed (A-Z) | Two-handed (A-Z) |
| Sign for “English” | Pulling toward the body | Specific finger-contact sign |
| Number System | Based on 10, often one-handed | Variations of 10, often two-handed |
| Grammar Structure | Topic-Comment | Topic-Comment (but different syntax) |
| Sentence Structure | Flexible, often OSV (Object-Subject-Verb) | Highly spatial and specific |
Frequently Asked Questions (FAQ)
Is there a universal sign language?
No, there is no universal sign language. There are roughly 300 different sign languages used worldwide. While International Sign (IS) exists for conferences, it is not a native language and has a limited vocabulary.
Can an ASL speaker learn BSL easily?
Yes. Because you already understand the spatial logic of sign language (using your body and the space around you to convey meaning), you will learn BSL much faster than a hearing person who has never signed before. However, you will essentially be learning a completely new vocabulary.
Why did America and Britain end up with different sign languages?
This was primarily due to the refusal of British educators in the 1800s to share their methods. America turned to France for help, which permanently aligned ASL with the French signing tradition rather than the British one.
Are ASL and BSL closer than English and Spanish?
Linguistically, no. The lexical similarity (shared words) between English and Spanish is actually higher (about 30-40% due to Latin roots) than the shared signs between ASL and BSL.
If I want to travel globally, which should I learn?
ASL is more widely understood internationally, especially in parts of Africa, Asia, and Central America, due to American educational outreach. However, if you plan to live or work in the UK, BSL is essential, as ASL will not be understood by the local Deaf community.
