Is it plausible to have two written forms of one spoken language that are so different as to be indecipherable?

Question

For a story idea in my head to work on paper, a character has to be able to fluently and eloquently speak a common language, to the point of being able to turn a phrase or make plays on words naturally, but they must not be able to comprehend that same language in written form.

Simple illiteracy is an option; very well-spoken people in history could not read. However the world is a near-future, post-industrial dystopia based on present-day Western culture, where the written word is everywhere and you don't get far without at least a grade-school reading comprehension level. That makes total illiteracy less plausible than it would be in an older time period; even with no formal education, you'd learn at least some basic words by necessity, and literacy begets more literacy.

I was thinking that a way around simple illiteracy might involve parallel development of written forms of the language; call them "upper" and "lower". Society is segregated by wealth or political power to such a degree that the poor use a completely different writing system, "lower", while the wealthy elite learn "upper" in schools, and while the two systems describe the words of the same spoken language, the basic symbolic concepts are so different that knowing one writing system is no help in deciphering the other (and societal pressure on both sides would preclude either class learning the other system). Reading either one knowing the other might be a similar experience as someone trying to read an English-language message transcribed into the Cyrillic alphabet, or the Arabic or Hebrew or Devanagari, with no knowledge of what sounds the symbols stand for. You might be able to sound it out with a primer of the alphabet in front of you, but that's what it'd take.

The question is, does this seem plausible? I realize this is opinionated, but if an answer can give a real-world example of cultures that can understand each others' spoken language but not their written one, that would be evidence this approach isn't so far fetched.

Answer 1

As a real life example, consider the Chinese writings Pinyin and Hanzi. Pinyin is a romanization of the sounds of the words, while hanzi is the characters like 漢字 *.

Now in the real world, people know how to read both, but it would be easy to construct a world where the lower class is only taught pinyin and the upper class is taught hanzi. This would fit well: Hanzi is considered to be the "real" Chinese characters, while the pinyin is often thought of as just a phonetic spelling to be used when the real characters cannot be written (such as on a qwerty keyboard)

*those two characters happen to be the characters for "Hanzi," because I'm someone who is amused by recursive things like that.

Answer 2

Urdu and Hindi are another example of this. The grammar and a large part of the vocabulary is essentially identical between the languages, but the writing in Urdu is based on Arabic and some vocabulary -- mostly formal or poetic language -- is from Arabic and Persian roots. In contrast, the writing in Hindi comes from Sanskrit, as do the corresponding poetic and formal language terms.

Someone who speaks Urdu or Hindi can readily converse with speakers of the other language (although they might recognize from certain word choices and/or accent that it is a speaker of the other language), but if they wanted, they could also probably make themselves unintelligible by switching to a very formal register of speech.

This multilingual sign demonstrates this. The top line is in Hindi (written in devanagri script) and the bottom right is in Urdu nastaliq script.

(You can see a direct comparison of the characters in wikipedia as well.)

Edit: I thought of more examples.

You mentioned Cyrillic. This was a script brought into Slavic lands by Christian missionaries, who adapted it from Greek characters. It is hypothesized that a runic script was used by the Slavs before this. People who were educated in the new script would very likely not be able to read the runes and vice versa.

How could I forget Japanese? They have 3 sets of characters used in their modern language, plus of course transliteration to Roman characters. They use kanji (adapted from Chinese hanzi), hiragana (for spelling words out in syllables) and katakana (generally used for spelling or foreign words and a few other uses). Foreign learners often start off learning Japanese with transliterated romaji (the Japanese equivalent of pinyin, essentially) and may never progress past hiragana to read kanji. Children start with katakana and hiragana as well.

You can also consider that a person who has vision impairment or a disorder such as dislexia might still be highly educated and articulate while having serious difficulties with the written form of language.

There are also languages with no native written form, such as Navajo.

Finally, you do not have to look back far in history to find a culture where a large group of people was socially segregated and not permitted to learn to read. In the US, before slavery was abolished, slaves were not permitted to learn to read. Some individuals were still able to become strong orators.

Answer 3

Yes, it is possible. In general there will be a trend towards a single script, as it has huge practical advantages. But there were and are examples of different scripts for the same language.

In Germany Fraktur was used far into the 20th century. Why? Just because (basically). Sure, it is the same alphabet but a different font. Yet a lot of people find it hard or are even not able to read Fraktur nowadays. Today everything is in Antiqua ("normal" letters).

Cursive is a different way to write the same alphabet. When "lower" classes first learned reading and writing it was usually with printed letters, not cursive. That was a style used in offices or by higher classes. Different style of cursive can vary significantly, e.g. this is Sütterlin which was used for a few years in Germany:

Both examples are just different ways to render the Latin alphabet.

Pinyin is a form to transcribe Chinese letters with the Latin alphabet. It is so useful for learning Chinese that a lot of learners just learn Pinyin and speaking but not reading or writing Chinese letters.

Oh, and while I am at Chinese letters: There exist two types of Chinese letters, traditional and simplified. They are still quite similar but different enough to confuse readers.

Mandarin Chinese also has the Zhuyin or bopomofo phonetic transcription system that is commonly used for text input on computers in Taiwan but not Mainland China.

Phonetic alphabets, notably the International Phonetic Alphabet, abstract from the underlying language. In theory you could read and pronounce a language just by using the IPA. Some "tourist dictionaries" use a simplified phonetic alphabet (based on the normal use of the source language) to achieve just that.

So it is possible to have different ways to write one language. Social segregation also is a possibility.

Answer 4

I am surprised that nobody mentioned Braille so far. It's an obvious contender for a script that can be read by a subset of people with little overlap to those reading the corresponding printed scripts.

Answer 5

What you describe (a single language with two scripts, used simultaneously) is plausible and has existed occasionally in history, although as others suggest the "steady state" tendency is towards a single script per language for practical reasons.

For instance, the Bosnian language can be written using either a Latin or Cyrillic script, and being able to read one doesn't imply an ability to read the other. Per Wikipedia, there are regional preferences as to one vs. the other, with some overlap.

There are also historical examples of languages changing scripts, typically for political reasons, which could plausibly create a generational split with older people preferring one script and younger people using a different one. E.g. Azerbaijani was written in an Arabic script until 1929, a Latin script from 1929–1938, Cyrillic from 1938 to 1991, and Latin (but not the same as 1929-38's!) from independence in 1991 until today. Each transition doubtless involved some people making the switch more slowly than others (and at least in the early 2000s there was a fair amount of public signage in both scripts).

For two scripts to remain in use indefinitely within the same population there would need to be some significant social force or pressure working against the tendency to prefer one or the other universally in the interest of communication. (And in not having to have twice as much public signage, etc.) But at the same time the separation between the users of each script couldn't be too great, or else over time the underlying languages would separate into different dialects, with the scripts being associated with one dialect or the other.

Answer 6

There is a real world example which might be even more fitting than Chinese (Pinyin vs. Hanzi where native speakers usually know both): The Hungarian runic alphabet.

It is completely different from the Latin alphabet, is written right-to-left, and is not completely mapped to the Latin alphabet (it's more compact, many symbols require 2 or 3 characters in the Latin form of the written language). It fell out of use around the 10th century, but was still used in remote locations until around the 15-16th century. This means that there was half a millenium where parts of the population spoke the same language but used a different script.

Most native speakers today cannot read it at all, but there are enthusiasts who learn it, and there are still works of literature published using the runic alphabet. In contrast with other runic scripts, whose languages are dead, the Hungarian runic alphabet can still be used perfectly with the contemporary Hungarian language and grammar.

Also, the the Hungarian Scout movement teaches this script, so many boy/girl scouts are fluent in it, although the general population isn't.

Answer 7

In Ancient Egypt there were several scripts that were used to write the language - the Hieroglyphics, the Hieratic form and the Demotic.

Their usage varied with times but primarily the former two were used for religious purposes - hieroglyphs went on stone walls and stelae, hieratic was committed to papyrus.

Demotic was chiefly used for writing down administrative matters.

Source.

The Turkish writing system underwent a transition from Arabic to Latin in the early 20th century, very few people can nowadays read Turkish in its older form.

Consider also the Norwegian language which has two official, written forms - Nynorsk and Bokmål (source) that each carry specific political connotations.

Answer 8

As a real world example just as you describe. Well, In Persian (Farsi) which is written using a derived version of Arabic alphabet, we have great number of Iranians living abroad in Europe and US who don't know the Persian Alphabet but have learned to speak the language from their parents. When writing, these people use English Alphabet to create a form known as (informally Fingilish = Farsi + English) which was also used on Qwerty keyboards without Persian alphabets. So for example these two sentences are read alike and are just the same.

• سلام دوست خوبم
• salam doost khubam

The case is that many native Iranians who are not familiar with English aren't able to read the second one and also the people living abroad can't read the first. So this situation totally matches your scenario.

There are people in between too who are familiar with Both alphabets not necessarily fluent English. In fact to read the second form you just need to know the sounds of the English Alphabet. And I suspect this situation would also be the case for Arabic and other languages with totally different form of Alphabet compared to English making it a common issue.
They can speak together but they can't read the other's writing

Answer 9

Sure. Many indian languages have similar sounds but very different scripts.

Malayalam and Tamil are probably the best examples here.

The two languages are barely mutually intelligible - some different word choices but enough that we understand ~50-70% of someone might be saying.

However a simple word like dog..

നായ് in malayalam (pronounced nāy) நாய் in tamil, also pronounced Nāy

So... as long as the sounds linked to letters are similar, its entirely possible to do that.

Answer 10

Up through the first half of the 20th Century or so, German had a system of script (handwriting) which differed from other European languages' scripts, and was not mutually intelligible with them although it could be learned in an hour or so.

Fraktur is simply a typeface, what we would call a font in the internet age, and not a separate alphabet. If you can read this, you can read Fraktur.

Tibetan has two systems for what we would call printing, U-Chen and U-Med. With the exception of some letters, they are mutually unintelligible, but knowing one, you can be taught the other in a day more or less.

Tibetan script, on the other hand, is a separate study and while based on the other two, looks like gibberish to the untrained eye.

Chinese had until 2004 a syllabic writing system solely used by women in part of Hunan Province, called 女書.

Mongolian since the 13th century has had multiple mutually unintelligible alphabets.

So the answer to the original question is an emphatic "yes".

Answer 11

while they describe the same phonemes of the same spoken language, the symbols are so different that knowing one is no help in deciphering the other

This seems to be based on the assumption that the different writing systems are both phonemic. In this case, I would expect learning Upper to be comparably easy, even if there is no letter-to-letter correspondence between the different writing systems due to multigraphs and other features.

I have made two experiences in this direction myself:

• I am German and it took me hardly any time to learn reading fraktur. If you want to try yourself, here is a website in fraktur and English, here is more material. (Disclaimer: I am involved in this project.)
• I recently read ˈÆlɪsɪz Ədˈventʃəz ɪn ˈWʌndəˌlænd (Alice’s Adventures in Wonderland in the International Phonetic Alphabet (IPA)), i.e., a book written in English and a completely phonemic writing system. This is not exactly comparable to what you propose as some IPA letters are taken from the latin alphabet and have the same phonetic value as in English, but there are sufficiently many deviations to give you some idea. I could read the book mostly fluently after a few pages.

If you want to experience your proposal yourself, Evertype published several renditions of Alice in Wonderland in exotic writing systems for the English language, some of which share no letters with the latin alphabet: [1], [2], [3], [4], [5], [6], [7], [list].

So, to address your question, I do not think it’s that plausible (depending on how strong you want the effect to be), if you insist on phonemicity. To address this, I would render Lower an entirely phonemic writing system and Upper a mostly unphonemic one, i.e., even worse than English. As a historical background, think of English not only having gone through the Great Vowel Shift but also a comparable consonant shift.

Answer 12

Other answers have mentioned Chinese. I'd like to point out the modern standard pin yin Romanization that's commonly used for typing, too. Everyone here on this English board can read "Beijing", but typing those same letters in the IME produces north capital: "北京".

Now my mother-in-law can’t type on a computer because she never learned pin yin, and her accent doesn’t match the people who came up with the transcription. She learned an earlier form of phonetic instruction (I suppose it would be this one) which is not roman-based. It’s fair to say that most Mandarin speaking people younger than 60 would find this unintelligible.

An example in History is Linear B script.

Imagine the surprise of the scholors figuring it out when the language turned out to be Greek!

The point to remember is that a writing system is not the same thing as a language.

Rather than simply different ways to draw a letter (making them hard to recognise), you have real differences between an idiographic or syllable based script and a phonetic script.

Another thing is moving from an "artistic" scheme such as Myan script to something more familiar to us. Myan "letters" are not written in a row but are combined into squares.

Furthermore they make a point of not writing the same letter the same way twice, which confused those who tried to read it later. In the above illustration the same word is shown 3 times!

There are certain graphic features that determine which meaning it has, but you have artistic freedom to represent the needed features in some drawing, and each block becomes a unique work of art.

So, a culture with a rich history of this kind of system may switch to a plain pedestrian system of letters that are minimal icons of the needed features (not a picture containing them), always the same, and set in neat rows, perhaps in conjunction with the advent of movable-type printing.

Even with the words and "letters" being the same, it would take quite a different mindset to read the old stuff.

---

in fiction

Here's some concrete examples of what you might use. This is far from simply different ways to write the same characters.

The historical writing system is more like Myan than anything we use today. Glyph-patterns are made from design elements, not specific renderings. E.g.

• 5 outward pointing points symmetrically arranged, like a star.
• a large round shape on the left and two smaller rounds stacked vertically to the right
• a wedge shape (open triangle) with small things inside

A scribe/artist would draw an artistic rendering incorporating the features, in a mini-mural where the order of finding the features is led through lines of composition and the context of the scene. For example, a pictorial of a river going through the kingdom will look like a sketch, but actually encode specific details of the story, which concerns the kingdom along the river.

What started as a clever way of including phonetic information in pictorial art to "speak the picture" evolved into a writing system that looks like Myan. A "character" is never drawn the same way twice, but you can find the meaning based on whether it's pointy or round, symmetry or lack of, number of elements, etc.

Larger scale order and arrangement act as modifiers for tense, imperitive vs question, etc.

Over time, a large collection of syllables were pared down to a phonetic system, but it was still drawn with "elements" not glyphs. Merchants and accountants have their own ideas and made stale writing for journals and ledgers.

A 5-pointed star became the glyph, etc. With simple essential line drawings used as a prototype for the pattern, each drawn in isolation. When it came to inventing printing and mass literacy, they moved to letters written in a neat row etc. like we understand.

Just as people study Shakespeare and calligraphy, well-cultured people in some subcultures learn the old idea of elements and apply the current alphabet and language, but draw them creatively in blocks, or as a form of poetry/art incorporate them into pictorial drawings.

Someone who didn't know that would be completely baffled at not even seeing writing (in the pictorial) or think the block form was an unrelated language.

Answer 13

Another example: Shorthand writing (coming in a number of varieties in itself) is - in my eyes - totally illegible even though it is in a way merely a specialized cursive handwriting with a few abbreviations

Answer 14

Apparently in Vietnam, during the French colonial period, there were FOUR competing writing systems in Vietnam: Chinese writing, a second system derived from Chinese writing, French, and the modern latin-character based Vietnamese writing system. The last of those slowly became completely dominant. (https://en.wikipedia.org/wiki/History_of_writing_in_Vietnam)

Answer 15

A non-reader or struggling reader can be highly eloquent in a language. That is not only plausible, but quite prevalent, actually. One sees this quite frequently in India among the rural landless farmers.

Coming to two scripts, a widely spoken language called Konkani has at least two variations, and is written in multiple scripts. I quote from Wikipedia: "Contemporary Konkani is written in Devanagari, Kannada, Malayalam, Persian, and Roman scripts. It is written by speakers in their native dialects. However, the Goan Antruz dialect in the Devanagari script has been promulgated as Standard Konkani."

Answer 16

Some other examples that haven't yet been brought up are as follows:

The Dungan language is a language spoken by Muslim Chinese (the Hui people) living in Kazakhstan and Kyrgyzstan. When these countries were absorbed into the Soviet Union, the Soviets engaged in a system of cyrillicisation, converting their existing Chinese-based writing to Cyrillic. As a result, we now have the following names for the language:

Dungan (Cyrillic): Хуэйзў йүян (Huejzw jyian)

Dungan (Chinese): 回族语言 (Hui Zhu Yu Yan)

As we can clearly see, the two writing systems are mutually unrecognisable.

The Kazakh language was also subject to similar cyrillicisation efforts, which resulted in the presence of three alphabets - the Cyrillic alphabet (official in Kazakhstan), the Arabic alphabet (official in China) and the Latin alphabet (unofficially used in Turkey). All three alphabets are not mutually recognisable. A comparison can be seen here:

Answer 17

Issac Asimov had a short story called Someday. It is set in a future where humans had forgotten how to read and write, they programmed computers by speech alone.

The two children in the story want to learn to read and write so they can pass along secret messages to each other.

Answer 18

Some excellent answers with the Chinese writings and German alphabets.

Another line you may think about is the realm of cryptography. It may play well into your story that the upper class are taught methods of quickly deciphering Caesar cyphers and possibly some others nearly as fast.

To avoid someone trying to nitpick at the ability of any human to decrypt on the fly, it could be an entirely fictional cypher method... let's call it the Fraktur cypher, just because it seems fitting.

It's not likely for something like this to occur in a society, but not implausible either. Just like the Chinese can learn two ways of writing with different characters, one could learn different methods of writing the same language with the same characters.

Or, you could ask someone that programs in Java, PHP, or Python to write a simple phrase.

Answer 19

Plenty of examples have been given, including the ones I could come up with (Japanese, braille, runic).

But few have addressed (beyond a simple yes/no) the worldbuilding aspect of this - "is it possible?" (which, in worldbuilding sense, usually means "is this the kind of thing that would make a reader whimper at the straining of their suspension of their disbelief?")

I think a class divide is certainly one possible way this could happen, but it need not be higher/lower classes.

There could also, as a historically supported example, be religious vs lay writings. The cloistered religious sects develop separately from the common world, so can and have either developed entirely separate writing styles, and even languages; or preserved older ones while the rest of the world moved on.

But in the future, perhaps the most obvious division would be a technocracy, with a writing system optimized for computer-based I/O. Consider, for example, chord-keying. If you teach kids chord-keying input from the get-go, it's silly to teach the letters, then the chord-pattern, then require them to mentally map from one to t'other. So you might only teach - at least initially - the list of which combination of the five keys is depressed for each letter/phoneme. Each letter could be represented, then, by a 5-pointed star with some of the points missing.

Realistically, though, to prevent linguistic drift, they would need to share a common sent of spoken media (movies, plays, songs, etc), but their written materials would either be unshared, or so trivially translated between encodings when passing between the groups that nobody ever thinks about it.

The latter is the most likely, and also a bit of a problem from a narrative standpoint. If the representations are just different fonts for the same codepoints, what's to stop someone just changing fonts in order to read most things. Augmented reality apps to translate roadsigns would also prevent confusion.

So, while it's possible that such a divided culture could form, it's not really possible, in a high-tech culture, for a non-shared font to cause any significant division.

Illiteracy is a much more believable thing; a subculture (perhaps a technocracy) which has moved past using the written word, would do it.

Answer 20

Let me add another real-world example: Malay (specifically Malaysian Malay which some consider distinct to Indonesian Malay (otherwise known as Indonesian)).

The traditional script for Malay was a modified Arabic script. During British rule, a lot of official correspondence were transliterated into the Roman (English) alphabet. Over time general literature started appearing in Roman alphabet.

After independence, the government decided to standardize the Malay language to use regular alphabets instead of Arabic script. The primary reason was typewriters - until the advent of computers (and widespread adoption of unicode) it was nearly impossible to type in Arabic. That's due to how ligatures work in Arabic. So schools standardized to use regular alphabets.

So we ended up with a generation gap. My grandfather's generation were mostly fully literate (owing to the fact that being able to read the Quran was considered critical to daily life). But my grandfather couldn't read regular alphabets. On the other hand, since the Arabic version of Malay is of lesser importance, I paid little to no attention to it in school. So I can barely read Malay in Arabic and can't write it at all. So we have two generations: my grandfather's generation who can read Arabic well and my generation who can read alphabets well. Remember, we're still talking about the same language here.

And that wasn't the only script change. The very oldest stone carvings in the Malay language were written in a script nobody use anymore. Then Malay transition to Sanskrit script when Hinduism and later Buddhism spread across the Malay Islands. Later to Arabic as I mentioned above when Islam came. Finally to regular Roman alphabets due to the influence of the British, Dutch and Portugese.

Answer 21

The first alphabet used for writing English was:

ᚠ ᚢ ᚦ ᚩ ᚱ ᚳ ᚷ ᚹ ᚻ ᚾ ᛁ ᛄ ᛇ ᛈ ᛉ ᛋ ᛏ ᛒ ᛖ ᛗ ᛚ ᛝ ᛟ ᛞ ᚪ ᚫ ᚣ ᛡ ᛠ

Later the alphabet used was:

ᚠ ᚢ ᚦ ᚩ ᚱ ᚳ ᚷ ᚹ ᚻ ᚾ ᛁ ᛄ ᛇ ᛈ ᛉ ᛋ ᛏ ᛒ ᛖ ᛗ ᛚ ᛝ ᛟ ᛞ ᚪ ᚫ ᚣ ᛡ ᛠ ᛢ ᛣ ᛥ ᚸ

While it's pretty easy to learn to read this, since it's a simple phonetic alphabet that works closely to how English uses the Latin alphabet (though closer to how English first used the Latin alphabet, when it also used Æ, Ð, Þ and Ƿ [and Ᵹ but it used that much as it also used g]) it's not hard to see how someone could be able to read English fluently in Latin letters and struggle with this.

Answer 22

When I saw this question I immediately thought of Chinese, with its Hanzi and Pinyin, but I was beaten to the punch for that one. But there is an important factor to consider: where do writing systems come from.

Most writing systems in use today are copies of other writing systems that pre-date them. The alphabet is probably the most versatile, yet it arose only a couple times in all of history: most alphabets were invented by people who already knew of alphabets.

Cyrillic was invented to better represent sounds in the local Slavic languages. Hangul was invented to make writing easier compared to the Chinese characters that were in use. Pinyin was invented to allow standard Mandarin words to be written using the roman alphabet, and to provide an easy way to document pronunciation. The Cherokee syllabary was invented by Sequoyah, who saw Europeans using "talking leaves". The actual invention of writing from non-writing is rare.

Thus, whatever motivation there is for maintaining a status quo of dual competing writing systems, it's unlikely that the writing would be mutually unintelligible as a sort of permanent condition, because both writing systems would have had to originate from somewhere, and it strains credulity that they were both independently invented in the same place without influencing each other and converging. Writing systems are usually invented by scholars, they take years or centuries to catch on, they compete with other writing systems from neighbouring regions (consider even the spelling differences between American and British English, or how various countries have switched from the Latin alphabet to Cyrillic or to Arabic or vice versa).

In general, with the possible exception of Chinese, anyone who is fluent in a language can usually pick up a new writing system for it fairly easily. Learning the alphabet/syllabary for a new language is usually the very first thing a foreign learner does, after all.

Thus, given that writing systems usually come from the elite and work their way down to the masses, and that learning a new one for a fluent speaker is easy, I think it's unlikely that there would be nearly no people who understand both systems. Sure, there are lots of Chinese people who can't really read Pinyin very well, and lots of Chinese speakers who can't read Hanzi at all, but Hanzi, being so difficult, only survives because the elite keep it around. Anyone who knows Mandarin Chinese, and has 10 minutes in training in Pinyin, or who knows Mandarin and English, could probably learn to read Pinyin text in a few hours. If the rich were using Hanzi and the poor were using Pinyin, any rich person who had any reason at all to write to the poor would have zero difficulty in doing so.

You might get more traction if you consider the problem the other way: Chinese characters are often used to write multiple languages. Cantonese and Mandarin are mutually unintelligble, like English and German are. But they both use the same writing system: Hanzi. However, it's common for a written Cantonese sentence to be totally incomprehensible to a Mandarin speaker (not so the other way around, as Mandarin is seen as the "standard", so there is immense pressure on Cantonese speakers to write as if they were using Mandarin). Also, any text written before about 1900 used Classical Chinese, which is similarly incomprehensible to modern readers despite using the same characters.

Answer 23

Serbo-Croat is generally considered one language. Serbs and Croats understand each other's spoken language - the differences are minimal - but Serbs write in Cyrillic (Russian alphabet), and the Croats write in the Latin alphabet (like English). An exact example of what you need! Except that learning an alphabet is pretty easy, and most educated people can read both, although not with equal fluency.

For your imaginary world, you could make both writing systems like Chinese, in which literacy requires learning 6,000 - 25,000 characters, depending on your level of "literacy". That would slow things down.

Answer 24

Yiddish (written in the Hebrew alphabet) was originally very similar to Middle German; Jews in other areas also developed Ladino (Judeo-Spanish) and Judeo-Arabic.

Going back to when literacy was less common, there were dialects of Aramaic written in both Hebrew and Greek scripts.

As to why, if you need to learn one alphabet to read religious texts, it's convenient to use it for everything.