It can be difficult for us anglophones to imagine that speech and writing could have little or nothing to do with each other. After all, our writing system more or less corresponds with our pronunciation. But to illustrate the possibilities, let’s consider three historical cases: Latin around the year 800 AD, modern Arabic, and Chinese.
Because of the grand expanse of the Roman Empire (and the lack of universal education), it was inevitable that regional versions of Latin would emerge. These dialects didn’t have their own written versions; instead, scribes conserved the Classical way of writing. This created a split in what Latin was: a high Latin, which was primarily written (especially championed by the Church), and a low Latin, which was primarily spoken. In fact, the low variety had no written form. Everyday people spoke the low variety, and educated people could read and write in the high variety. Though these budding Romance languages were linguistically distinct from Classical Latin, they were all considered the same catholic Latin. The people were little bothered (at first anyway) that written Latin had little to do with spoken Latin; that’s just the way it was. As we know, the multiple versions of Latin eventually gave rise to what we know today as the Romance languages. Written Spanish, Portuguese, French, Italian and Romanian are nothing more than validated dialects of Latin.
There are more varieties of Arabic than there are Arab nations. Moreover, not all speakers of Arabic dialects can understand each other. Notwithstanding, there’s only one way to write in Arabic: Egyptian Standard, the form used in the Koran.
Every Chinese character represents a word or idea. What many people don’t realize is that there are many Chinese dialects, and some of them are not even linguistically related. This means that the character 耳, which means “ear,” is pronounced differently in different dialects. To take this further, consider that a sentence in written Chinese may be pronounced differently—and with a completely different grammatical system—depending on the dialect. Moreover, Korean and Japanese, which linguistically have nothing to do with Chinese, both have adopted some Chinese characters to represent their own languages.